Related Applications This application is a continuation-in-part of U.S.

Application Serial No. 07/397,732, filed 8/23/89, which is a continuation-in-part of U.S. Application Serial No. 07/157,451, filed February 17, 1988. Applications Nos. 07/397,732 and 07/157,451 are incorporated herein by this reference.

Field of the Invention

This invention relates to soluble rigid-rod polymers having rigid-rod backbones and pendant, solubilizing organic groups attached to the backbone, and to methods for preparing the polymers. This invention also relates tc copolymers comprising rigid-rod segments, having solubilizing organic groups attached to the rigid-ro segments. The rigid-rod polymers can, for example, b used as self-reinforced engineering plastics, can be use in combination with flexible coiled polymer binders fo the preparation of high tensile strength molecula composites and can be used as matrix resins for fiber containing composites.

Background of the Invention

High-performance fiber-polymer composites are rapidl achieving a prominent role in the design and constructio of military and commercial aircraft, sports and industria

equipment, and automotive components. Composites fill th need for stiffness, strength, and low weight that canno be met by other materials. The most widely utilized high performance fiber-polymer composites are composed o oriented carbon (graphite) fibers embedded in a suitabl polymer matrix. To contribute high strength and stiffnes to the composite, the fibers must have a high aspect rati (length to width) . Fibers may be chopped or continuous. The mechanical properties of chopped fiber composite improve greatly as the aspect ratio increases from l t about 100. Mechanical properties still improve but at slower rate for further increases in aspect ratio. Therefore, aspect ratios of at least about 25, an preferably of at least about 100 are desirable for choppe fiber composites. Composites prepared with continuou fibers have the highest stiffness and strength. Fabricatingfiber-containingcomposites, however, require significant manual labor and such composites cannot b recycled. Furthermore, defective and/or damaged composit materials cannot be easily repaired.

Molecular composites are high-performance material which are much more economical and easier to process tha conventional fiber-polymer composites. In addition molecular composites can be recycled and are repairable Molecular composites are composed of polymeric material only, i.e., they contain no fibers. Such molecular com posites can be fabricated much more simply than fiber polymer composites.

Molecular composites are materials composed of a rigid rod polymer embedded in a flexible polymer matrix. Th rigid-rod polymer can be thought of as the microscopi equivalent of the fiber in a fiber-polymer composite Molecular composites with the optimum mechanica properties will contain a large fraction, at least 3 percent, of rigid-rod polymers, with the balance bein polymeric binder. Molecular composites may contain eithe oriented or unoriented rigid-rod polymers.

A molecular composite requires that the rigid-ro polymer be effectively embedded in a flexible, possibl coil-like, matrix resin polymer. The flexible polyme serves to disperse the rigid-rod polymer, preventin bundling of the rigid-rod molecules. As in conventiona fiber/resin composites, the flexible polymer in a molec lar composite helps to distribute stress along the rigi rod molecules via elastic deformation of the flexibl polymer. Thus, the second, or matrix-resin, polymer mus be sufficiently flexible to effectively surround t rigid-rod molecules while still being able to stretch up stress. The flexible and rigid-rod polymers can al interact strongly via Van der aals, hydrogen bonding, ionic interactions. The advantages of molecular co posites can only be realized with the use of rigid-r polymers.

Most of the linear polymers produced commercially tod are coil-like polymers. The chemical structure of t polymer chain allows conformational and rotational moti along the chain so that the entire chain can flex a adopt coil-like structures. This microscopic proper relates directly to the macroscopic properties of flexur strength, flexural moduli, and stiffness. If fewer less extensive conformational changes are possible, stiffer polymer will result.

Two technical difficulties have limited molecul composites to laboratory curiosities. Firstly, the pri art relating to molecular composites calls for mere blending or mixing a rigid-rod polymer with a flexib polymer. It is well known in the art, however, that, general, polymers of differing types do not mix. That i homogeneous single phase blends cannot be obtained. Th rule also applies to rigid-rod polymers and, thus, t early molecular composites could be made with only sma weight fractions of a rigid-rod component. In the systems, an increase in the fraction of the rigid-r component led to phase separation, at which point

molecular composite could no longer be obtained.

The second technical difficulty is that rigid-rod polymers of significant molecular weight are exceedingly difficult to prepare. The technical problem is exemplified by the rigid-rod polymer, polyparaphenylene.

During the polymerization of benzene, or other monomer leading to polyparaphenylene, the growing polymer chain becomes decreasingly soluble and precipitates from solution causing the polymerization to cease. This occurs after the chain has grown to a length of only six to ten monomer units. These oligomers, i.e. , rigid-rod polymers, are too short to contribute to the strength of a composite. A lack of solubility is a general property of rigid-rod polymers, hence, synthesis of all such rigid-rod polymers is difficult.

The solubility problem may be avoided in the special case in which the product polymer contains basic groups which can be protonated in strong acid and the polymerization can be conducted in strong acid. For example, rigid-rod polyquinoline can be prepared in the acidic solvent system dicresylhydrogenphosphate/m-cresol, because the quinoline group interacts with the acidic solvent, preventing precipitation. However, the resulting polymers are soluble only in strong acids, making further processing difficult.

Before molecular composites can become a practical reality, ' the problems of (a) blending the rigid-rod and flexible components into a stable homogeneous phase, an (b) the low solubility of the polymer, must be overcome.

Summary of the Invention

In one embodiment, rigid-rod polyphenylenes provided i accordance with the present invention are line polyphenylenes in which the polymer chain has at lea about 95% 1,4 linkages, and incorporates penda solubilizing side groups. Rigid-rod polyphenylenes may homopolymers or copolymers having more than one type 1,4-phenylene monomer unit. The number average degree polymerization (DP _n ») is greater than about 25.

As used herein, DP _n is defined as follows:

DP _n = (number of monomer molecules present initially)/(number of polymer chains in the system)

In another embodiment of the present inventio segmented rigid-rod polyphenylene copolymers are provide The segmented copolymers of the present invention compri one or more rigid-rod polyphenylene segments and one more non-rigid segments, wherein the rigid-r polyphenylene segments have a number average segme length (SL _n ) of greater than about eight.

As used herein, the number average segment length defined by:

SL _n = (number of rigid monomer molecules prese initially) /(the total number of rigid segments at the e of the reaction)

and is essentially the average number of monomer units each rigid segment. Each polymer chain typically contai many rigid segments. However, some may contain less th others, or only one rigid segment. The number avera segment length may be approximated by:

SL _n = (number ■ of rigid monomer molecules prese initially)/(number of kinked or flexible monomer molecul present initially + number of polymer chains at the end

the reaction)

The rigid-rod and segmented rigid-rod polymers of the present invention are unique in that they are soluble in one or more organic solvents. The polymer and the monomers demonstrate a significant degree of solubility in a common solvent system so that the polymer will remain in a dissolved state in the polymerization solvent system. The rigid-rod and segmented rigid-rod polymers of the present invention are made soluble by pendant solubilizing organic groups (side groups or side chains) which are attached to the backbone, that is, to the monomer units. The pendant organic groups impart increased solubility and meltability to the polymer by disrupting interactions between the rigid chains, providing favorable interactions with organic solvents, increasing the entropy (disorder) of the chains, and causing steric interactions which twist the phenylene units out of planarity. Therefore, such polymers can be considered to be self-reinforced plastics or single-component molecular composites. Thus, the rigid-rod and segmented rigid-rod polymers of the present invention have incorporated rod-like and coil-like com¬ ponents into a single molecular species. The rigid-rod or segmented rigid-rod polymer can also be mixed with a coil¬ like matrix resin to form a blend, wherein the pendant organic groups act as compatibilizers to inhibit phase separation.

Rigid-rod polymers produced in the past are, in general, highly insoluble (except in the special case of polymers with basic groups which may be dissolved in strong acid) and are infusible. These properties make them difficult, and often impossible, to prepare and process. We have found, surprisingly, that the incorporation of appropriate pendant organic side groups to the polymer substantially improves solubility and fusibility. Earlier work has suggested that such pendant

side groups do not increase the solubility of rigid-r polymers. However, by increasing the size of the si chain, by placing side chains so that steric repulsio prevent adjacent phenylene ring from lying in the sa plane, by placing side chains in a non-regular (rando stereoche ical arrangement, and/or ' by matching i properties (principally, polarity and dielectric constan to the polymerization solvent, rigid-rod and segment rigid-rod polymers of substantial molecular weight can prepared. For example, when the polymerization is carri out in a polar solvent, such as dimethylacetamide (DMA or N-methylpyrrolidinone (NMP) , the solubilizing organ side groups will preferably be polar and will have hi dielectric constants, such as ketones, amides, esters a the like.

The rigid-rod backbone/flexible side-chain polymers the present invention can be prepared in common solven and can be processed with standard methods to give stable, single-component, molecular composite or se reinforced polymer useful for structural and oth applications requiring high strength and modulus.

The rigid-rod and segmented rigid-rod polymers of t present invention when used in a blend with a flexib polymer are the primary source of tensile strength a modulus of the resulting molecular composite. Su molecular composites may be homogeneous single pha blends, blends having microphase structure, or multi-pha blends having macroscopic structure. Pendant side grou can be chosen to increase compatibility between the rigi rod or segmented rigid-rod polymer and the flexib polymer. The more compatible system will have finer pha structure. The most compatible will be miscible a homogeneous single phase. The rigid-rod and segment rigid-rod polymers of the present invention can be blend with thermoplastics, thermosets, liquid crystalli polymers (LCP's), rubbers, elastomers, or any natural synthetic polymeric material. It is known in

literature that the properties of chopped fiber composites improve as the aspect ratio of the fiber increases from 1 to about 100, with less relative additional improvement on further increases of aspect ratio. It is also known in the literature that in simple blends of rigid-rod and flexible polymers, the strength and moduli of the molecular composite blend is a function of the aspect ratio of the rigid-rod component, and that these blends phase separate on heating (W. F. Hwang, D. R. Wiff, C. L. Benner, and T. E. Helminiak, Journal of Macromolecular

Science - Physics. B22. pp. 231-257 (1983)). Preferably, when employed as a self-reinforcing plastic, the rigid-rod polymer of the present invention will have an aspect ratio of at least 100, that is, the backbone of the polymer (not including side groups) will have straight segments with an average aspect ratio of at least 100. For structural and aerospace uses, for example, aspect ratios greater than 100 are desirable. For other less demanding uses, such as cabinets, housings, boat hulls, circuit boards and many others, the rigid-rod polymer backbone can have an aspect ratio of 25 or more. Similarly the segmented rigid-rod polymers of the present invention when employed in structural applications will have segments with aspect ratios greater than about 6, preferably greater than about 8.

The high strength and stiffness of the soluble rigid- rod and segmented rigid-rod polymers of the present invention are directly related to the aspect ratio of the straight segments comprising the polymer chains. For the purposes of the present invention, by aspect ratio of a monomer unit is meant the length to diameter ratio of the smallest diameter cylinder which will enclose the monomer unit, including half the length of each connecting bond, but not including any solubilizing side group(s) , such that the connecting bonds are parallel to the axis of the cylinder. For example, the aspect ratio of a polyphenylene monomer unit (-C ₆ H ₄ -) is about 1.

The aspect ratio of a polymer segment is taken to be the length to diameter ratio of the smallest diameter cylinder which will enclose the polymer segment, includin half the length of the terminal connecting bonds, but no including any attached side groups, such that the axis o the cylinder is parallel to the connecting bonds in th straight segment.

For the purposes of the present invention, aspect rati will only be applied to rigid-rod polymers, rigid-ro monomer units, or straight segments of rigid-rod polymers.

The aspect ratio of a rigid-rod polymer will be taken t mean the average aspect ratio of its straight segments. The above definition of aspect ratio is intended t provide a close analogy to its common usage with respec to fiber-containing composites.

The polymer backbone of rigid-rod polymers provided i accordance with one embodiment of this invention will b substantially straight, with no flexibility that coul result in bends or kinks in the backbone, that is, the will have a high aspect ratio. Accordingly, the polymer should be made employing processes which are not prone t the formation of occasional kinks or other imperfectio which may interfere with the rigidity of the backbone Nonetheless, almost all chemical reactions have sid reactions, and, accordingly, some phenylene monomer unit incorporated in the final polymer will not have 1, linkages, but rather, will have 1,2 or 1,3 linkages (non parallel covalent bonds) . Other side reactions are als possible leading to non-phenylene linkages, for example ether linkages or phosphorous linkages. However, th rigid-rod polymers provided in accordance with practice o the present invention will have at least 95% 1,4 linkage and preferably, at least 99% 1,4 linkage. Any 1,2 or 1, linkage in the polymer chain will reduce the averag length of straight segments. Thus, a polymer chain o length 1000 monomer units having 99% 1,4 linkage and wil contain, on average, 11 straight segments with a numbe

average segment length (ΞL _n ) equal to approximately 91.

Rigid-rod polymers provided in accordance with this invention which have greater than 99% parallel covalent bonds, i.e., where greater than 99% of the backbone linkages are 1,4 linkages, will be exceptionally stiff an strong and will be useful where high tensile and flexura strengths and moduli are required, as in aerospac applications. Rigid-rod polymers having between about 95% and 99% parallel covalent bonds will be useful for les stringent applications, such as body panels, molded parts, electronic substrates, and myriad others. In on embodiment of the present invention, non-rigid-rodmonome units may intentionally be introduced into the polymer, t promote solubility or to modify other properties such a T _g or elongation to break.

The polymers provided in accordance with practice o the present invention can be homopolymers or can b copolymers of two or more different monomers. Th polymers of the present invention comprise a rigid-ro backbone comprising at least about 25 phenylene units preferably at least about 100 phenylene units, wherein a least about 95%, and preferably 99%, of the monomer unit are coupled together via 1,4 linkages and the polymer an its monomers are soluble in a common solvent system Solubility is provided by solubilizing groups which ar attached to the rigid-rod backbone, that is, to at leas some of the monomer units of the backbone. Preferably, solubilizing group is attached to at least 1 out of 10 monomer units. For the purposes of the present invention, the ter

"soluble" will mean that a solution can be prepared con taining greater than 0.5% by weight of the polymer an greater than about 0.5% of the monomer(s) being used t form the polymer. By "solubilizing groups" is meant functional group which, when attached as side chains to the polymer i question, will render it soluble in an appropriate solven

syste . It is understood that various factors must b considered in choosing a solubilizing group for particular polymer and solvent, and that, all else bein the same, a larger or higher molecular weight solubilizin group will induce a higher degree of solubility.

Conversely, for smaller solubilizing groups, matching th properties of the solvent and solubilizing groups is mor critical, and it may be necessary to have, in addition other favorable interactions inherent in the structure o the polymer to aid in solubilization.

By the term "rigid-rod monomer unit" it is meant th basic, organic, structural units of the polymer rigid-ro backbone chain in which the covalent bonds connecting the to adjacent monomer units are parallel regardless o conformational changes within the rigid-rod monomer unit

For the purposes of this invention rigid-rod monomer unit will be limited to 1,4-phenylene units, including an attached side chain, i.e., solubilizing groups.

The term "monomer unit" will always be used in th present invention to mean "rigid-rod monomer unit." I the instances where a flexible or non-rigid-rod monome unit is discussed, it will be indicated as a "non-rigi monomer unit." Most non-rigid monomer units cannot attai a conformation in which the bonds to the polymer chain ar parallel, for example, the 1,3-phenylene group or th

4,4'-diphenylether group. However, some non-rigid monome units will admit a conformation in which the bonds to th polymer chain are parallel, such as the phenylene amid type non-rigid monomer units of a polymer provided b DuPont Company under the trademark KEVLAR (polyamide o

1,4-phenylenediamine and terephthalic acid) . Polymer comprised of such non-rigid monomer units are "pseudo rigid" due to the possibility of bent or kinked conforma tions. Rigid-rod polymers are, in general, stiffer tha pseudo-rigid polymers.

By the term "monomers," for the purposes of the presen invention, it is meant the immediate chemical precursor

to the polymer. Because most of the polymerization reactions described herein are condensation polymerizations, a monomer will typically lose one or more functional group(s) with respect to the corresponding monomer unit. For example, the monomer dichlorobenzene

(C ₅ H ₄ C1 ₂ ) polymerizes to a polymer with phenylene (C ₅ H ₄ ) monomer units.

The solubility of rigid-rod and segmented rigid-rod polymers provided in accordance with this invention is achieved by the attachment of pendant, solubilizing organic groups to at least some of the monomer units of the polymers. One who is skilled in the art will recognize that it is difficult to determine a priori what combinations of organic substituent (pendant organic group) , polymer backbone, polymer configuration, solvent system, and other environmental factors (e.g., temperature, pressure) will lead to solubility due to the many complex interactions involved. Indeed, as is mentioned above, other workers have found that pendant organic side groups do not provide a substantial increase in the solubility of rigid-rod oligomers and polymers. We, however, have discovered general strategies for the rational design of soluble rigid-rod and segmented rigid- rod polymer systems. For example, if the rigid-rod or segmented rigid-rod polymers are to be synthesized in polar solvents, the pendant solubilizing organic groups of the polymer and the monomer starting material will be a group that is soluble in polar solvents. Similarly, if the rigid-rod or segmented rigid-rod polymers are to be synthesized in non-polar solvents, the pendant solubilizing organic group on the rigid-rod polymer backbone and the monomer starting material will be a group that is soluble in non-polar solvents.

Various factors dependent on the nature of the backbone itself also affect the inherent solubility of the polymer.

The orientation of the individual monomer units, especially with regard to the positioning of pendant

-13 - organic substituents, has been shown to have an effect on the solubility properties of polymers. In particular, 2,2'-disubstituted biphenylene units incorporated into aromatic polyesters (H.G. Rogers et al, U.S. Patent No. 4,433,132; February 21, 1984), rod-like polya ides (H.G.

Rogers et al, Macro olecules 1985, 18, 1058) and rigid pol imides (F.W. Harris et al. High Performance Polymers 1989, 1, 3) generally lead to enhanced solubility, presumably not due to the identity of the substituents themselves but to sterically enforced non-coplanarity of the biphenylene aromatic rings. Extended, planar chains and networks of conjugated aromatics exhibit good stacking and strong intermolecular interactions and are generally expected to exhibit high crystallinity and, thus, poor solubility. Random distribution of side chains in homo- polymers and especially copolymers will enhance solubility by lowering the symmetry of the polymer chain, thereby decreasing crystallinity.

The rigid-rod and segmented rigid-rod polymers (homopolymers and copolymers) provided in accordance with the present invention will have at least one monomer unit for each 100 monomer units in the rigid-rod backbon substituted with a solubilizing organic group, o preferably one monomer unit for each ten monomer units i the rigid-rod backbone substituted with a solubilizin organic group. In general, for relatively smal solubilizing side groups a higher degree of substitutio is needed for good solubility. In many instances no mor than 50% of the monomer units should be unsubstituted, fo example copolymers of 1,4-dichlorobenzene and 2,5 dichlorobenzophenone show appreciable decrease i solubility with 10% unsubstituted units, and only low M material can be prepared at greater than about_ 50 unsubstituted units. The solubilizing organic groups whic are substituted on, attached to, or pendant to the monome units are organic molecules that have solubility in one o more organic solvent system(s) . In order that relativel

s all organic groups, that is, those of a molecular weight of less than about 300, are capable of providing appropriate solubility, other favorable backbone interactions, as described above, may be required. For instance, at least one 2,2'-disubstituted biphenylene fragment would be required in the backbone for each 200 monomer units, and preferably for each 20 monomer units, and more preferably for each four monomer units in a polyparaphenylene type polymer. In embodiments of the invention, where the rigid-rod polymer is a homopolymer, the same organic or pendant group(s) occur(s) on each monomer unit. The side chains are chosen to enhance solubility, especially in the polymerization solvent system. For example, polar groups, such as N,N- dimethylamido groups, will enhance solubility in polar solvents.

In one embodiment of the invention, the polymer is a copolymer of two or more rigid monomer unit types, and the majority of monomer units are substituted with solubilizing organic groups. The polymer can be formed from two different monomer units or monomers, three different monomer units or monomers, four different monomer units or monomers, and so on. At least one out of every 100 (1%) , preferably 10% and more preferably 50% of the monomer units in the rigid-rod backbone has a solubilizing organic group attached to it.

In another embodiment of the invention, the polymer is a copolymer having rigid-rod segments with segment length (S-L _jj ) of at least about eight, and non-rigid segments of any length. In the case where rigid-rod segments are separated by only a single non-parallel linkage, the non- parallel linkages represent kinks in an otherwise straight polymer molecule, as for example would be introduced with isolated 4, ' -diphenyl ether monomer units. In this case the angle between the rigid-rod segments is fixed. If the non-rigid monomer units have more than one non-paralle linkage, or if the non-rigid segments have length greater

than one, the angle between the rigid-rod segments is no fixed, and the copolymer as a whole has much greate flexibility. In the case of long non-rigid blocks th copolymer may be considered a single component molecula composite, where the rigid blocks reinforce the flexibl blocks.

Where rigid-rod polyphenylene segments are used in block copolymer with non-rigid segments, the rigi segments will have a dramatic effect on the physical an mechanical properties of the copolymer for relativel small aspect ratio of the rigid segments.

Brief Description of the Drawings

These and other features, aspects and advantages of the present invention will be more fully understood when considered with respect to the following detailed description, appended claims, and a accompanying drawings, wherein:

FIG. 1 is a semi-schematic perspective view of a multi- filament fiber provided in accordance with practice of the present invention; FIG. 2 is a semi-schematic perspective view of a roll of free-standing film provided in accordance with practice of the present invention;

FIG. 3 is a semi-schematic cross-sectional view of a semi-permeable membrane provided in accordance with practice of the present invention;

FIG. 4 is a semi-schematic perspective view of a radome provided in accordance with practice of the present invention mounted on the leading edge of an aircraft wing;

FIG. 5. is a schematic cross-sectional side view of a four-layer printed wiring board provided in accordance with practice of the present invention;

FIG. 6 is a semi-schematic perspective view of a non- woven mat provided in accordance with practice of the present invention; FIG. 7 is a semi-schematic perspective view of a block of foam provided in accordance with practice of the present invention; and

FIG. 8 is a semi-schematic fragmentary cross-sectional side view of a multi-chip module provided in accordance with practice of the present invention.

FIG. 9 is a semi-schematic side view, including an enlarged section, of a fiber containing composite comprising a polymer provided in accordance with the present invention.

Detailed Description of the Invention

In a first preferred embodiment, the rigid-rod polym provided in accordance with practice of the pres invention are linear polyphenylenes which incorpor parallel covalent bonds (1,4 linkages) between mono units. Such rigid-rod polymers will have at least 95% linkages, and preferably at least 99% 1,4 linkages, i. the polymers will have high aspect ratios.

The rigid-rod polymers of the present invention h the following general structure:

Structure I wherein each R _χ , R ₂ , R ₃ , and R ₄ are independently cho solubilizing groups or hydrogen. The structure is mean represent polymers having mixtures of monomer units well as those having a single type of monomer unit. structure does not imply any particular orientati order, stereochemistry, or regiochemistry of R grou Thus, the polymer may have head-to-head, head-to-ta random, block or more complicated order. The partic order will depend on the method of preparation and reactivity and type of monomers used.

In another preferred embodiment of the pre invention, rigid polyphenylene segments are separate flexible monomer units or flexible segments or block give a segmented rigid-rod polymer. In this case flexible segments contribute to solubility processability as well as the solubilizing side group the rigid polyphenylene segments. The rigid backbon the rigid segments provide the segmented rigid-rod pol with a high degree of stiffness and strength, and modify other properties, such as creep resista

flammability, coefficient of thermal expansion, and the like, to a degree proportional to the relative amounts of rigid and flexible segments. In fact, such physical and mechanical properties can be precisely adjusted by adjusting the rigid fraction. For example, the coefficient of thermal expansion of a segmented rigid-rod polymer may be adjusted to match a particular material by controlling the amount of rigid monomer relative to flexible monomer used in its preparation. Dihaloaromatic monomers of Structure II may be used in the preparation of segmented rigid-rod polymers.

Structure II

where - a are independently chosen from solubilizing side groups and H wherein G is -0-, -S-, -CH ₂ -, -CY ₂ -, -OCH ₂ -, -OAT-, -0(ATO) _n -, -(CH ₂ ) _n -, "(CY ₂ ) _n -, -CO-, -C0 ₂ -, -CONY-, -0(CH ₂ CH ₂ 0) _n -, ~(CF ₂ ) _n -, -COArCO-, -C0(CH ₂ ) _n C0-, -C(CF ₃ ) ₂ -, -C(CF ₃ )(Y)-, -NY-, -P(=0)Y-, X is Cl, or Br, or

I and Ar is an aromatic group, heteroaromatic group, or substituted aromatic group, and Y is independently selected from the group consisting of H, F, CF ₃ , alkyl, aryl, heteroaryl, or aralkyl group, and n is l or greater.

In order to provide significant improvement in physical and mechanical properties over flexible polymers the segmented rigid-rod polymers of the present invention should have rigid segments with number average segment length (SL _n ) of at least about 8.

One such exemplary embodiment of the structure of a polymer comprising rigid-rod polyphenylene segments

separated by flexible monomer units (the segmented rigid- rod polymer of the present invention) is as follows:

Structure III

wherein:

is a rigid-rod polymer segment, wherein each R _l R ₂ , R ₃ and R ₄ on each monomer unit, independently, is H or a solubilizing side group, and -[A] _m - is a non-rigid segment, for example as derived from non-rigid monomers of Structure II; wherein the rigid-rod polyphenylene segments have number average segment length SL _n of at least about 8, n is the average number of monomer units in the rigi segment, m is the average number of monomer units in th flexible segment and m is at least 1.

In one exemplary embodiment, the segmented rigid-ro polymer of the present invention has structure III wherei -A- is:

wherein B ¹ -B ⁴ are independently selected from the grou consisting of H, C _λ to C ₂₂ alkyl, C ₆ to C ₂₀ Ar, alkaryl, F,

CF ₃ , phenoxy, -COAr, -COalkyl, -C0 ₂ Ar, -C0 ₂ alkyl, wherein Ar is aryl or heteroaryl. The flexible monomer units in this case may be derived from substituted 1,3- dichloroarenes. In another exemplary embodiment -A- is 1,3-phenylene and is derived from 1,3-dichlorobenzene.

Other flexible monomers and monomer units may be used as are apparent to one skilled in the art.

The segmented rigid-rod polymers may be used in the same ways as the rigid-rod polymers including compression and injection molding, extrusion, to prepare films and fibers, in blends, alloys and mixtures, as additives, as matrix resins, and in other ways apparent to those skilled in the art.

Other polymer systems have been described in the past as rigid or rod-like but must not be confused with true rigid-rod polymers provided in accordance with this inven¬ tion. For instance, long chain para-oriented aromatic polyamides and polyesters often exhibit ordering, due to various intermolecular forces, into rod-like assemblies and consequently demonstrate some of the advantages (e.g. , high strength) and disadvantages (poor solubility) of true rigid-rod polymers. Such polymer systems are actually only "pseudo-rigid" because ester and amide linkages are not inherently rigid or parallel and only adopt parallel configurations under certain conditions. At lower concentrations or higher temperature they may behave like flexible polymers. It is known in the art that the theoretical stiffness of aromatic polyamide and polyester backbones is lower than a polyphenylene backbone. Stiffer polymers will of course have greater reinforcing properties.

The rigid-rod and segmented rigid-rod polymers of the present invention will have at least one monomer unit for each 100 monomer units in the rigid-rod backbone substituted with a solubilizing organic group.

Preferably, the polymer will have at least about one monomer unit in ten substituted with solubilizing organic

groups. More preferably, the polymer will have more tha one monomer unit per 10 monomer units substituted wit solubilizing organic groups. The solubilizing organi groups which are substituted on, attached to, or pendan to, the monomer units are organic molecules that hav solubility in one or more organic solvent system(s) . Solubilizing organic groups which can be.used include, bu are not limited to, alkyl, aryl, alkaryl, aralkyl, alky or aryl amide, alkyl or aryl thioether, alkyl or ary ketone, alkoxy, aryloxy, benzoyl, phenoxybenzoyl, εulfones, esters, i ides, imines, alcohols, amines, an aldehydes. Other organic groups providing solubility i particular solvents can also be used as solubilizin organic groups. In an exemplary embodiment, a polymer of Structure or III is provided where at least one of the R groups is

wherein X is selected from the group consisting o hydrogen, amino, methyla ino, dimethylamino, methyl phenyl, benzyl, benzoyl, hydroxy, methoxy, phenoxy

-SC ₆ H ₅ , and -OCOCH _3#

In another exemplary embodiment, a polymer of Structur

I or III is provided where at least one of the R group is:

and wherein X is selected from the group consisting o

methyl, ethyl, phenyl, benzyl, F, and CF ₃ , and n is 1, 2, 3, 4, or 5.

In another exemplary embodiment, a polymer of Structure I or III is provided wherein one of _lf R ₂ , R ₃ or R ₄ is selected from the group consisting of -CR ₅ R ₆ Ar where Ar is aryl, R ₅ and R ₆ are H, methyl, F, Cl to C20 alkoxy, OH, and R ₅ and R ₆ taken together as bridging groups -OCH ₂ CH ₂ 0- , -OCH ₂ CH(CH ₂ OH)0-, -OC ₆ H ₄ 0- (catechol) , -OC ₆ H ₁₀ O- (1,2- cyclohexanediol) , and -OCH ₂ CHR ₇ 0- where R ₇ is alkyl, or aryl.

In yet another exemplary embodiment, a polymer of Structure I or III is provided wherein R _χ is -(CO)X where X is selected from the group consisting of 2-pyridyl, 3-pyridyl, 4-pyridyl, -CH ₂ C ₆ H ₅ , -CH ₂ CH ₂ C ₆ H ₅ , -naphthyl and 2-naphthyl or other aromatic, fused ring aromatic or heteroaromatic group.

In an additional exemplary embodiment, a polymer of Structure I or III is provided wherein at least one of the R groups is -S0 ₂ X and wherein X is selected from the group consisting of phenyl, tolyl, l-naphthyl, 2-naphthyl, methoxyphenyl, and phenoxyphenyl or other aromatic or substituted aromatic groups.

In a further exemplary embodiment, a polymer of Structure I or III is provided wherein at least one of the R groups is -NR ₅ R _S and wherein R ₅ and R ₆ may be the same or different and are independently chosen from the group consisting of alkyl, aryl, alkaryl, hydrogen, methyl, ethyl, phenyl, -COCH ₃ and R ₅ and R ₆ taken together as bridging groups -CH ₂ CH ₂ OCH ₂ CH ₂ -, -CH ₂ CH ₂ CH ₂ CH ₂ CH ₂ -, an -CH ₂ CH ₂ CH ₂ CH ₂ - and the like.

In another exemplary embodiment, a polymer of Structur I or III is provided wherein at least one of the R group is -N=CR ₅ R ₆ and R ₅ and R ₆ may be the same or differen and are independently selected from the group consistin of alkyl, aryl, alkaryl, -H, -CH ₃ , -CH ₂ CH ₃ , phenyl, tolyl, methoxyphenyl, benzyl, aryl, Cl to C22 alkyl, and R ₅ an R ₆ taken together as bridging groups -CH ₂ CH ₂ OCH ₂ CH ₂ -,

-CH ₂ CH ₂ CH ₂ CH ₂ CH ₂ -, and -CH ₂ CH ₂ CH ₂ CH ₂ - and the like.

The rigid-rod and segmented rigid-rod polymers of th present invention are made in accordance with well-know chemical polymerization and addition reactions or by nove processes described herein. Such processes fo preparation of the rigid-rod and segmented rigid-ro polymers of the present invention employ chemical polymer ization addition reactions in solvent systems in which th rigid-rod and segmented rigid-rod polymers and the monome starting materials are both soluble. Of course, th monomer and polymer will not demonstrate complet solubility under all conditions. The polymer will likel demonstrate solubility only up to a certain weigh fraction, depending on the exact solvent-polymer pair an other factors, such as temperature. Obviously, it is no necessary for the monomer to be completely soluble in solvent for a chemical reaction to proceed. As is wel known in the art, compounds demonstrating limite solubility in a chemical mixture will completely react t give product due to the equilibrium between dissolved an undissolved monomer, that is, undissolved monomer wil slowly undergo dissolution as that fraction of dissolve monomer is continuously exhausted in the reaction. As i discussed above, the monomer and polymer are considere "soluble" in a particular solvent system when a solutio can be prepared which contains at least about 0.5% b weight monomer and at least about 0.5% by weight polymer

In order to assure solubility of the monomer an polymer in the solvent, the properties of the appende organic groups must be matched to those of the desire solvent. Thus, if the rigid-rod and segmented rigid-ro polymers are to be synthesized in polar solvents, th pendant solubilizing organic groups of the polymer and t monomer starting material will be groups that are solubl in polar solvents. Similarly, if the rigid-rod a segmented rigid-rod polymers are to be synthesized in no polar solvents, the pendant solubilizing organic group

the rigid-rod and segmented rigid-rod polymer and the monomer starting material will be a group that is soluble in non-polar solvents. We have found that it is very important to match the dielectric constant and dipole moment of the solubilizing organic groups to that of the solvent to achieve solubilization. For instance, to achieve solubility in polar aprotic solvents such as NMP, the solubilizing organic groups should have dielectric constants greater than about 5 and dipole moments greater than about 1.5.

In general, relatively long organic side chains, e.g. those with a molecular weight of greater than about 300, are preferred to enhance solubility of the rigid-rod polymers of the present invention. Surprisingly, however, we have found that rigid-rod polyphenylene type polymers, that is, rigid-rod polymers comprised of linear polyparaphenylene type monomer units having Structure I can be solubilized with relatively short organic groups appended, e.g. , organic groups with molecular weights from about 15 to about 300. Solubility is typically achieved by a combination of favorable interactions acting together. For instance, solubility can be achieved in rigid-rod polyparaphenylenes substituted with the very small (i.e., low molecular weight) but very polar side chains hydroxy (-0H) and amino (-NH ₂ ) .

Planar aromatics tend to stack well, causing them to be very crystalline and, thus, have low solubility. This tendency to stack can be reduced by forcing adjacent aromatic rings , e.g., monomer units, to twist away from planarity. This can be effected by the addition of substituents next to the covalent bonds linking the monomer units, leading to significant numbers of disubstituted 2,2'-biaryl type linkages. Such units have been shown to increase solubility when incorporated into other types of polymer systems. Therefore, to achieve maximum solubility of short chain appended polyparaphenyl¬ enes, either the nature of the monomer units or of the

polymerization should be such that significant numbers o disubstituted 2,2 '-biphenyl linkages are introduced int the polymer. For example, if every monomer unit has single non-hydrogen side group (R ₁₇ *H, R ₂ =R ₃ =R ₄ =H) , then regular head-to-tail catenation will lead to no 2,2' disubstituted linkages, however, a regular head-to-hea catenation will lead to 50% of the linkages having 2,2' disubstitution and 50% 2,2'-unsubstituted. A perfectl random catenation will give 25% 2,2 ^■ -unsubstituted, 50 2,2'-monosubstituted and 25% 2 , 2'-disubstituted linkages

We have found, in particular, that rigid-ro polyphenylenes having benzoyl or substituted benzoy solubilizing side groups are soluble in amide solvents for example N-methylpyrrolidinone (NMP) , and high M rigid-rod polyphenylenes can be prepared in amid solvents. Poly-1,4-(benzoylphenylene) , 1, may be prepare from 2,5-dichlorobenzophenone by reductive coupling wit a nickel catalyst. The resulting polymer dopes have ver high viscosities and may be purified by precipitation int ethanol or other non-solvents. The dried polymer i soluble in NMP, di ethylacetamide, phenylether, m-cresol sulfurie acid, anisole, 5% NMP in chloroform chlorobenzene, and similar solvents.

Poly-1,4-(benzoylphenylene) , 1

The molecular weight of polymer 1 will depend on t exact conditions of polymerization, including monomer catalyst ratio, purity of the reactants and solven dryness of solvent, oxygen concentration, and the lik The method by which the zinc is activated great influences the molecular weight. It appears that t highest MW is obtained when the zinc is most active, th

is when the reaction time is shortest. It is important that the zinc be free flowing powder which does not contain clumps which may form in the drying steps. The method of zinc activation given in the examples below is effective and convenient, however, other methods of activation are suitable including sonication, distillation, and treatment with other acids followed by rinsing and drying. It is also important that the zinc be well mixed during, and especially at the beginning of, the reaction.

Molecular weight may be measured by many methods, most of which give only a relative molecular weight. Two of the most widely used methods are viscosity and gel permeation chromatography (GPC) . The intrinsic viscosity, [rj] , may be related to the molecular weight by the Mark-

Houwink Equation:

[77] = k-MW ⁰ For flexible polymers α is typically about 0.6, however, for rigid polymers is usually greater than 1 and may be as high as 2. In order to determine absolute molecular weight, k and must be obtained from other methods, or estimated using standards having structure similar to the polymer under study. Since there are no known rigid-rod polymers soluble in organic solvents there are no good standards for the polyphenylenes described here. We can make a crude estimate based on the expected relationship between viscosity and molecular weight for rigid-rods as has been applied to polyparabenzobisthiazole and polyparabenzobisoxazole {J.F. Wolfe "Polybenzothiazoles and Oxazoles." in Encyclopedia of Polymer Science and

Engineering] John Wiley & Sons, Inc., New York, 1988; Vol. 11, pp. 601-635.}:

[77] * 4.86xl0 ²⁰ (d _h °- ² /M _je ) (M^/M^) ¹ ' ⁸

where [rj] is in dL/g, d _h is the hydrodynamic diameter of a chain element in cm, and M,. is the mass-per-unit length in g/cm. If d _h is taken to be 10~ ⁷ cm (lnm) , the _t of

trans-PBT is 2.15 x 10 ⁹ cm ^-1 , the K. of cis-PBO is 1.83 10 ⁹ cm ^-1 , M _η = M _W (M _Z /M _W ) ^{4 9} , and M _z /M _w =1.3 then the weight-average molecular weight can be determined from th simple measurement of [ η ^~ \ . For polymer 1 we estimate d _h « 1.5xl0 ^~7 cm; M _£

4.19X10 ⁹ cm" ¹ = MW/£ = 180/4.3A; and [ η ] = 2.4xl0 ^~8 -MW ¹ ' ⁸ Thus the polymer of Example 1 below has [ η ] = 7.2 dL/g an an estimated viscosity average MW of 51,000.

Intrinsic viscosity is useful as a relative measure o molecular weight even without Mark-Houwink constants. Fo comparison the highest reported viscosity for polyphenylene is 2.05 dL/g {M. Rehahn, A.-D. Schlϋter, G Wegner Makromol. Chem . 1990, 191 , 1991-2003}.

Similarly, molecular weights as determined by GP require a calibration standard, and no rigid-rod standard are available. The GPC data given in the examples belo are reported using a polystyrene standard and ar therefore expected to be much higher than the actua weight average molecular weights. The soluble rigid-rod polymers of the present inventio can be made by any method which is highly selective fo 1,4-phenylene regiochemistry. Non-limiting examples o such reactions are: nickel catalyzed coupling o 4-chloroaryl Grignard reagents, nickel or palladiu catalyzed coupling of 1,4-arylhalides, palladium catalyze coupling of 4-chlorophenylboronic acids, Diels-Alde coupling of monosubstituted 2-pyrones (J.N.Braham T.Hodgins, T.Katto, R.T.Kohl, and J.K.Stille Macromolecules. 11. 343-346, 1978.), anodic oxidation o 1,4-dialkoxybenzene, and addition polymerization o cyclohexadienediol derivatives. The polymer will be a least 25 monomer units in length, preferably at least 10 monomer units in length, and, most preferably, longer tha 100 monomer units. The polymer can be a homopolymer of single monomer or a copolymer of two or more differe monomers or monomer units. The segmented rigid-r polymers of the present invention can be made using t

same methods as for the rigid-rod polymers, except that a non-rigid-rod monomer is added to the rigid-rod monomers before or during polymerization.

Processes for preparing unsubstituted or alkyl εub- stituted polyphenylenes from aryl Grignard reagents are described in T. Yamamoto et al, Bull. Chem. Soc. Jpn. , 1978, 51, 2091 and M. Rehahn et al. Polymer, 1989, 30, 1054. Paraphenylene polymers (made up of monomer units of Structure I) can be prepared by the coupling of Grignard reagents of paradihalobenzenes catalyzed by transition metal complexes. Thus, a mixture of 4-bromo- phenylmagnesium bromide (1 mole) and 4-bromo-3-alkyl- phenylmagnesium bromide (1 mole) , the alkyl group having an average chain length of about 24 carbon atoms, will react in an ether solvent in the presence of a transition metal complex to yield a polyparaphenylene rigid-rod polymer having about one out of two monomer units sub¬ stituted with a long chain alkyl group. The transitio metal-catalyzed coupling reaction proceeds selectively an quantitatively under mild conditions. In another varian of the reaction, 1,4-dibromobenzene (0.5 mole) and a 1,4 dibromobenzene substituted with a long-chain alkoxy grou (1 mole) can be coupled in the presence of magnesium meta and a transition metal catalyst in an inert solvent, suc as ether, to produce a polyparaphenylene rigid-rod polyme having on the average about two monomer units out of thre monomer units substituted with a long-chain alkoxy group. A variety of dihalogenated benzenes (monomers of Formul IA) , biphenyls (monomers of Formula IB) , terphenyl (monomers of Formula IC) , can be polymerized using thes methods ( ~Ri ₂ ^of monomers IA, IB and IC ar independently chosen from solubilizing groups and H) Dibromo-substituted compounds (X=Br) are the compounds o choice for the reaction; however, in many instances, th dichloro compound (X=C1) can also be used, if the reactio can be initiated. We have found that the NiCl ₂ (2,2* bipyridine) transitionmetal catalystworks satisfactoril

for this reaction.

IC

When the rigid-rod or segmented rigid-rod polymers ar prepared under Grignard conditions, the following types o organic groups may react with the Grignard reagents causing undesirable side reactions: alkyl halides amides, esters, ketones, and the like. Thus, such group should be avoided as solubilizing side groups when th polymers of the present invention are prepared usin Grignard conditions.

Coupling of the paradihaloarene monomers is preferabl carried out with nickel or palladium catalysts with zin as the reducing agent. We have discovered that suc polymerizations give soluble rigid-rod polyparaphenylen polymers with high molecular weights in virtually quanti tative yields. This approach has distinct advantages since a wider variety of solvents can be employed, such a N,N-dimethylformamide (DMF) , N-methylpyrrolidinone (NMP) hexamethylphosphoric triamide (HMPA) , benzene tetrahydrofuran (THF) , and dimethoxyethane (DME) . Thi coupling reaction can also be used with monomers havin specially reactive groups, such as nitrile and carbony groups. In addition, zinc is less expensive and easier t handle than magnesium. Similar reactions to prepar biphenyl derivatives and non-rigid polymer systems ha been demonstrated by Colon (I. Colon and D. Kelsey, J Org. Chem.. 1986, 51, 2627; I. Colon and C. N. Merria U.S. Patent No. 4,486,576, December 4, 1984)

Unfortun tely, this technique was demonstrated to be unsatisfactory to produce high molecular weight polymers from substituted dihalobenzene type monomers due to deactivation of the nickel catalyst by the substituents. It was, therefore, unexpected when we discovered that certain mixtures of anhydrous nickel compounds, triaryl- phosphine ligands, inorganic salt promoters, and zinc metal were efficient for the preparation of high molecular weight polyparaphenylenes from the reductive coupling of paradihalobenzene monomer units substituted with solubilizing organic groups in anhydrous polar aprotic solvents. It is highly recommended to utilize highly purified (preferably greater than about 99% pure) paradihalobenzene monomer from which any water or other aprotic impurities have been removed. For instance, a mixture of one equivalent of anhydrous nickel chloride, three equivalents of sodium iodide, seven equivalents of triphenylphosphine, and 50 equivalents of zinc metal is effective in the polymerization of about 30 equivalents of substituted paradichlorobenzene monomer. The polymerization reaction is preferably carried out at about 50°C but is effective from about 25°C to about 100°C. The ratio of equivalents of monomer to equivalents of nickel catalyst can vary over the range from about 10 to about 5000, and the ratio of equivalents of zinc to equivalents of monomer is at least 1.0. The ratio of equivalents of phosphine ligands to equivalents of nickel catalyst varies from about 3.0 to about 10 or more. The concentration of phosphine ligands should be about 2.5 M or more to prevent the formation of highly unsaturated nickel zero complexes which lead to undesired side reactions. Use of inorganic salt promoters is optional. When used, the inorganic salt promoter should be at a concentration of about 0.05 M to 1 M, preferably about 0.1 M. Non-limiting examples of inorganic salt promoters are alkali iodides, alkali bromides, zinc halides and the like. These promoters reduce or eliminate the induction period which is typical

of nickel catalyzed couplings of aryl halides. When rigid rod or segmented rigid-rod polymers are prepared by nicke catalyzed coupling, the following types of side groups ma interfere with the reaction and should be avoided halides, acids, alcohols, primary and secondary amines nitro groups, and any protic groups. If side groups o these types are desired they should be introduced i protected form.

When using the nickel-triarylphosphine catalys described above, one must be careful to selec sufficiently reactive monomers in order to obtain hig molecular weight polyparaphenylenes. If the reactivity i too low, we believe that side reactions are more likely t occur, which can limit molecular weight and/or deactivat the catalyst. Also, the two halide groups of th paradihaloarene monomers may have different reactivities depending on the identity and location of the substituen groups. Therefore, the orientation (e.g. head-to-head head-to-tail, and tail-to-tail) of the monomer group along the polymer backbone will be largely determined b the relative reactivities of the halo groups of th monomer. Relative reactivities are also important t consider when copolymers are being prepared. Fo instance, it is desirable to choose comonomers of simila reactivities when a completely random distribution of th different monomer groups is desired in the copolymer Conversely, it may be desirable to choose monomers wit significantly different reactivities in order to obtai block-type copolymers, although molecular weight may b limited if the reactivity of any of the monomers is to low.

In general, it is desirable to have some knowledge o the reactivity of monomers or comonomers in order to mak some predictions about the quality, structure, o properties of the resulting polymers or copolymers. Fo instance, we have utilized a simple semi-quantitativ procedure (see Example 29) for determining the relativ

coupling reactivities of various monohaloarene model compounds using nickel-triarylphosphine catalysts. The results of such experiments can then be used to estimate the relative reactivities of correspondingparadihaloarene monomers or comonomers. In general, we have found that to obtain the highest molecular weights, monomers must be chosen such that high conversions are achieved within about 4-6 hours when carried out under the preferred reaction conditions described above. For instance, if it is desired to prepare the corresponding polyparaphenylene from the reductive coupling of 2,5-dichlorobenzoylmorpholine, one would consider the relative reactivities of 3-chlorobenzoylmorpholine (fast) and of 2-chlorobenzoylmorpholine (slow) and would expect a head- to-head and tail-to-tail orientation and that molecular weight might be somewhat limited. Similarly, if one wanted to prepare a copolymer comprising paradichlorobenzene and 2,5-dichlorobenzophenone comonomers, then the relative reactivities of chlorobenzene, 2-chlorobenzophenone, and 3- chlorobenzophenone should be considered (e.g. from Example 29, we see that the reactivities are similar, and fast, so a random copolymer with high molecular weight would be expected) .

Aryl group coupling to afford polyphenylenes has also been effected by the palladium catalyzed condensation of haloaryl boronic acids as reported by Y. H. Kim et al. Polymer Preprints. 1988, 29, 310 and M. Rehahn et al, Polymer. 1989, 30, 1060. The para-haloaryl boronic acid monomers required for formation of polyparaphenylenes can be prepared by the monolithiation of the paradihalobenzene with butyl lithium at low temperature and subsequent trimethylborate quench and aqueous acid workup. These polymerizations are carried out in aromatic and ethereal solvents in the presence of a base such as sodiu carbonate. Therefore, this type of reaction is suitabl

for producing polyparaphenylenes substituted with organi groups such as alkyl, aryl, aralkyl, alkaryl polyfluoroalkyl, alkoxy, polyfluoroalkoxy, and the like The choice of solvents for the various polymerizatio or condensation reactions will be somewhat dependent o the reaction type and the type of solubilizing organi groups appended to the monomers. For the condensation o aryl monomers employing Grignard reagents with transitio metal catalysts, the solvents of choice are ethers, an the best solubilizing side chains are ethers, such a phenoxyphenyl, and long-chain alkyls. Anodic polymeri zation is done in acetonitrile-type solvents, and ether and aromatic side chains, such as phenylether, and benzy would be the favored side chains. The monomer units are known or can be prepared b conventional chemical reactions from known starting mater ials. For example, the 1,4-dichlorobenzopheno derivatives can be prepared from 2,5-dichlorobenzoic ac via 2,5-dichlorobenzoyl chloride followed by Fried Crafts condensation with an aromatic compound, for examp benzene, toluene, diphenylether and the like. T paradihalobenzene monomers substituted at the 2 positi with an alkoxy group can be prepared from t corresponding 2,5-dihalophenol by allowing the phenol the presence of sodium hydroxide and benzyltr ethylammoniu chloride to react with the corresponding haloalkyl, such as benzyl bromide. Substitut dichlorobenzenes may also be prepared from the inexpensi 2,5-dichloroaniline by diazotization of the amine grou to yield corresponding p-dichlorobenzenediazonium sal

The diazonium salt is treated with nucleophiles in t presence of copper salts to form the desired product.

In addition to being soluble in organic solvent surprisingly, the polymers of the present invention may thermally processed, for example, by compression moldi or by injection molding. For example, injection mold specimens of poly-l,4-(4'-phenoxybenzoylphenylene) ,

have flexural moduli greater than 1 million pounds pe: square inch (MSI) .

Poly-l,4-(4"-phenoxybenzoylphenylene) , 2

Some of the polymers of the present invention will melt t o f o r m f r e e f l o w i n g l i q u i d s . Poly-l,4-(methoxyethoxyethoxyethoxycarbonylphenylene) ,3, is a freely flowing liquid at about 250°C if protected from air. It was totally unexpected that high MW rigid- rod polyphenylenes having side groups with molecular weights less than 300 could be compression molded. It was even more surprising that such polymers would melt without decomposing.

Polymer 3 In addition to solubility, the side groups impar fusibility. That is the side groups lower the T _g and mel viscosity to ranges suitable for thermoprocessing.

Polyparaphenylene devoid of side groups is essentiall infusible. It can be sintered at high temperature an pressure but it cannot be injection or compression molde or thermoformed by conventional techniques. Likewis other known rigid-rod polymers such a poly(benzobisthiazole) and rigid-rod polyquinolines ar not thermoformable. The polymers of the present inventio

are thermoformable. Rigid-rod polyphenylenes having lon very flexible side groups will melt. For example, t triethylene glycol side groups of 3 imparts a low T _g a T _m . Even short side groups impart fusibility. Polymer has side groups with molecular weight 105 and exceptional flexibility. It was unexpected that polyme 1 and 2 could be compression molded. Surprisingly, ev relatively high molecular weight 1 ([n])6, MW _W )500,000 GPC vs polystyrene standard) can be compression molded translucent to transparent panels.

The polymers of the present invention have very hi tensile moduli. Isotropic cast films and compressi molded coupons have given moduli in the range of 1 milli pounds per square inch (MPSI) to 3 MPSI. For the sa polymer the modulus increases as the molecular weig increases. The high modulus is a clear indication of t rigid-rod nature of these polymers. Tensile moduli f polyphenylenes have not been reported, presumably becau known polyphenylenes have molecular weights too small give film flexible enough to be tested.

It is well known that rigid-rod polymers form liqu crystalline solutions if their aspect ratio and hen molecular weight increase beyond a critical value. Ma pseudo-rigid-rod polymers are known to form liqu crystalline phases as they melt. It was therefo unexpected to find that the rigid-rod polymers l, 2 and neither form liquid crystalline solutions nor thermotrop liquid crystalline phases, even at intrinsic viscosity over 7 and GPC molecular weights over 500,000. This is advantage in molding operations where liquid crystallini can lead to poor weld lines, poor transverse mechanic properties, poor compressive strength, and a fibrill morphology. Polymers 1 and 2, in contrast give near isotropic molded panels, show no evidence crystallinity, and do not have a fibrillar structure. T low crystallinity of the polymers of the present inventi is advantageous in many applications including moldin

matrix resins, optical polymers, and blending.

Because the polymers of the present invention are soluble and will melt they can be processed using a wide variety of techniques. Polymer solutions may be spun into fibers by wet spinning, wherein the polymer solution is forced through an orifice directly into a non-solvent. The polymer forms a continuous fiber as it precipitates and may be washed dried and further processed in one continuous operation. Spinnerets having multiple orifices may be used to form poly-filament yarn. The orifices may have shapes other than round. The polymers of the present invention may also be dry jet wet spun, wherein an air gap is maintained between the spinneret and the non-solvent.

Fibers may also be spun from a gel state. Gels have significantly different visco-elastic properties than liquids, and spinning fiber or casting film from a gel will often give products with dramatically different physical properties than those processed from simple solutions. Fibers spun from gels will can have a high degree of molecular orientation resulting in stronger, stiffer fibers.

Fibers may also be spun directly from the melt. This method is environmentally the cleanest since it does not require any solvents. The polymer is heated and forced through an orifice. Orientation may occur at the orifice as a result of expansive flow. Orientation may also be induced by controlling the tension on the fiber to cause stretching. Multifilament yarn may also be spun from the melt. Fibers spun by any method may be further treated to influence physical and chemical properties. Further stretching, heating, twisting, etc. may be used to improve mechanical properties. Chemical treatments such as surface oxidation, reduction, sizing, coating, etching, etc. may be used to alter the chemical properties such as interaction with adhesives, matrix resins, dyes, and the like, and may also alter physical properties, such as

appearance, tensile strength, flexural strength, resistance to light, heat and moisture, and the like.

Referring to FIG. 1, there is shown a semi-schemati view of a multi-filament fiber 10 comprising a pluralit of mono-filaments 12, comprising a rigid-rod or segmente rigid-rod polymer provided in accordance with practice o the present invention.

The polymers of the present invention may also b fabricated into film. As with . fibers many differen methods may be used to form films. Since the rigid-ro and segmented rigid-rod polymers of this invention ar both soluble and meltable, all of the conventional fil forming techniques are applicable. Films may be cast fro solution onto a substrate and the solvent removed eithe by emersion into a non solvent or by oven drying, under vacuum or inert atmosphere if necessary. Eithe continuous or batch processes may be used. Films may als be extruded from the melt through a slit. Films may als be formed by blow extrusion. Films may also be furthe processed by stretching and/or annealing. Special film such as bilayers, laminates, porous films, textured film and the like may be produced by techniques known in th art.

Films, like fibers, may be oriented by stretching Stretching along one dimension will result in uniaxia orientation. Stretching in two dimensions will giv biaxial orientation. Stretching may be aided by heatin near the glass transition temperature. Stretching ma also be aided by plasticizers. More complex processe such as applying alternating cycles of stretching an annealing may also be used with the polymers of th present invention.

Referring to FIG. 2, there is shown a roll 20 of free standing film 22, formed from a rigid-rod or segmente rigid-rod polymer, prepared in accordance with practice o the present invention.

The polymers of the present invention may also b

fabricated into membranes useful for separations of mixed gases, liquids and solids. Membranes may be produced by the usual methods, for example asymmetric membranes by solvent casting. Filters may be prepared by weaving fibers prepared as described above, or forming non-woven mats from chopped fibers or fibrous material produced by precipitation of polymer solution with a non-solvent.

Referring to FIG. 3, there is shown a cross-sectional side view of a semi-permeable membrane 30 comprised of a rigid-rod or segmented rigid-rod polymer provided in accordance with practice of the present invention. As a result of the casting technique, the upper surface 32 has very small pores and is denser than the lower surface 34, which has courser pores. The asymmetric structure of the membrane provides for higher selectivity and faster flow rates.

Coatings may also be formed by any of the established techniques, including but not limited to: coating from solution, spray coating of solution, spin coating, coating from a latex, powder coating, laminating preformed films, spray coating molten droplets, and coating from the melt.

Various molding techniques may be used to form articles from the polymers of the present invention. Powders, pellets, beads, flakes, reground material or other forms of rigid-rod and segmented rigid-rod polyphenylenes may b molded, with or without liquid or other additives, premixed or fed separately. Rigid-rod and segmente rigid-rod polyphenylene may be compression molded, th pressure and temperatures needed being dependent on th particular side groups present. Exact conditions may b determined by trial and error molding of small samples. Upper temperature limits may be estimated from therma analysis such as thermogravimetric analysis. Lowe temperature limits may be estimated from T _g as measure for example by Dynamic Mechanical Thermal Analysis (DMTA) .

Some suitable conditions for particular side groups ar given in the examples below.

Some of the polymers provided in accordance with th present invention may also be injection molded. T determine if a particular polymer can be injection molde it is necessary to measure the melt viscosity under shear typically using a capillary melt flow rheometer

Typically polymers having melt viscosities of less tha 10,000 poises at shear rates greater than 10 ³ sec ^-1 can b injection molded. To be suitable for injection molding polymers must also remain fluid (ie. without gelling o solidifying) at the molding temperature during the moldin operation. It is also desirable if the polymer can b remelted several times without degradation, so tha regrind from molding processes can be used. Particula examples of rigid-rod and segmented rigid-ro polyphenylenes which meet these requirements are give below. However, injection molding is not limited to th particular side groups shown, and the utility of injectio molding for any of the polymers of the present inventio may readily be determined by one skilled in the art. Referring to FIG. 4, there is shown a schematic view o a radome 42 molded from a rigid-rod or segmented rigid-ro polymer provided in accordance with practice of th present invention. The radome 42 is shown mounted on th wing structure 44 of an aircraft. The radome i essentially a radar transparent cover which i structurally self-supporting.

In addition to films and fibers, other forms of rigid rod and segmented rigid-rod polyphenylenes may be produce by extrusion. Non-limiting examples include: angle channel, hexagonal bar, hollow bar, I-beam, joining strip rectangular tube, rod, sheet, square bar, square tube, section, tubes, or other shapes as is required for particular application. Related to extrusion pultrusion, wherein a fiber reinforcement is continuous added to an extruded polymer. The polymers of the prese invention may be used as a thermoplastic matrix which pultruded with fibers, such as carbon fiber or gla

fiber. Alternatively, the polymers of the present invention may be used as the fiber for pultrusion of a thermoplastic having a lower processing temperature. In the first case, composites with exceptional moduli and compressive strength will result. In the second case, lower cost thermoplastics having moderate moduli and strength can be formed into composites with high moduli and strength by the incorporation of rigid-rod or segmented rigid-rod polyphenylene fibers. Such a composite is unique in that the reinforcing fibers are themselves thermoplastic and further processing at temperatures above the fiber T _g will result in novel structures as the fibers physically and/or chemically mix with the matrix. Many of the forms of rigid-rod and segmented rigid-rod polyphenylenes alluded to above, i.e., fiber, film, sheet, rod, etc. , may be further processed and combined with other material to yield articles of higher value. Sheet stock may be cut, stamped, welded, or thermally formed. For example, printed wiring boards may be fabricated fro sheet or thick films by a process wherein copper is deposited on to one or both sides, patterned by standar photolithographic methods, etched, then holes are drilled, and several such sheets laminated together to form finished board. Such boards are novel in that they do no contain any fiber reinforcement. Such reinforcement i not necessary because of the unusually high modulus of th instant polymers. Such boards are also unique in tha they may be bent into non-planar structures, b application of heat and pressure, to better fit limite volume enclosures, such as laptop computers. Sheet an film may also be thermoformed into any variety o housings, cabinets, containers, covers, chassis, plates, panels, fenders, hoods, and the like. Referring to FIG. 5, there is shown a semi-schemati cross-sectional side view of a four-layer wiring board 50 The board is comprised of rigid-rod or segmented rigid-ro

polymer dielectric 52. Copper lines 54 are embedded i the dielectric 52 to form the inner two circuit planes Copper lines 56 on the surface of the board form the tw outer circuit planes. A via 58 is used to connec conducting lines in different planes. The via 58 connect conducting lines in the two outer planes with the line i one of the inner planes. The dielectric 52 can be a pur rigid-rod polymer, a segmented rigid-rod polymer, a blend a laminate or fiber-containing composite. Referring to FIG. 6, there is shown a non-woven mat 6 which consists of chopped fibers 62 comprised of a rigid rod or segmented rigid-rod polymer provided in accordanc with practice of the present invention. Such non-wove mats may be used as filters or the like. Referring to FIG. 7, there is shown a block of foam 7 comprising a rigid-rod or segmented rigid-rod polyme provided in accordance with practice of the presen invention.

Rigid-rod and segmented rigid-rod polyphenylenes ma also form the dielectric layers of multichip modules

Multichip modules (MCM) are similar to printed wiri boards except that integrated circuits are mount directly on the MCM without prior packaging. T integrated circuits may be more closely packed, savi total system volume, reducing propagation delays, a increasing maximum operating frequency, among oth benefits. The basic structure of a multichip module shown in Fig 8. There are alternating layers dielectric and current carrying conducting lines. Mea for electrically and physically attaching integrat circuits is provided, as well as interconnection to t next highest level of packaging. Such MCM structures m be fabricated by many diverse processes. Because t rigid-rod and segmented rigid-rod polyphenylenes of t present invention both melt and dissolve in comm solvents any of the currently practiced methods of M fabrication may be applied.

Referring to FIG. 8, a semi-schematic cross-sectional side view of an MCM, provided in accordance with practice of the present invention is shown. The MCM is typically (but not necessarily) fabricated using photolithographic techniques similar to those used in integrated circuit fabrication. As a non-limiting example an MCM may be constructed by spin coating a layer 82 of rigid-rod or segmented rigid-rod polyphenylene onto a silicon substrate 84, having a plurality of resistors 86 on its surface, to thereby form a dielectric layer. The polyphenylene layer

82 may be further cured thermally or chemically if necessary. A layer of copper 88 is deposited onto the polyphenylene layer, and a layer of photoresist (not shown) is deposited, exposed, developed and the underlying copper etched through the developed pattern in the resist.

A second layer 90 of rigid-rod or segmented rigid-rod polyphenylene is spin coated and cured. Vias (not shown) to the underlying copper lines are cut, for example by laser drilling. Additional layers of copper 92 and dielectric 94 are added and patterned. Completed MCM's may have six or more alternating layers depending on the circuit complexity. The dielectric for MCM's may also be fabricated by laminating films, by spray coating or by other methods known in the art. The rigid-rod or segmented rigid-rod polyphenylene layer itself may be photosensitive, allowing additionalmethods of processing. Photosensitivity of the rigid-rod or segmented rigid-ro polyphenylene will depend on the side group and additio of catalysts and sensitizers. The polymers of the present invention may also b combined with a variety of other polymers, additives, fillers, and the like, collectively called additives, before processing by any of the above or other methods. For example, the polymers of the present invention may b blended with some amount of a more flexible polymer t improve the extension-to-break of the blend. Thus, finished products formed from such a blend, e.g. , film,

sheet, rod or complex molded articles will be relativel tougher. Rubbers may be added to toughen the finishe product. A liquid crystalline polymer may be added t reduce melt viscosity. Many other combinations will b apparent to those skilled in the art. The particula amounts of each additive will depend on the applicatio but may cover the range from none (pure rigid-rod o segmented rigid-rod polyphenylene) to large amounts. A the amount of additives becomes much larger than th amount of rigid-rod polyphenylene the rigid-ro polyphenylene itself may be considered an additive.

Polymers comprising the rigid-rod and segmented rigid rods of the present invention can also be used i structural applications. Because of their high intrinsi stiffness, parts fabricated with rigid-rod or segmente rigid-rod polymers will have mechanical propertie approaching or equal to fiber containing composites. I many applications where fibers are necessary fo structural reasons they cause other undesirable effects For example, rado es for airborne radar are typicall constructed of glass fiber reinforced composites, but th glass fibers lead to signal loss and degradation of rada performance. Fiberless radomes comprised of rigid-rod o segmented rigid-rod polymers would improve rada performance over composite radomes. Fiberless radome would also be easier to fabricate than composite radomes Fiberless radomes comprising rigid-rod or segmented rigid rod polymers provided in accordance with the presen invention could be injection or compression molded o stamped from sheet, or machined from stock.

Rigid-rod and segmented rigid-rod polymers can also b used to advantage in fiber containing composites as th matrix resin. As is known in the art the compressiv strength of composites is related to the modulus of th matrix resin. Referring to FIG. 9, a composite 10 comprising reinforcing fibers 102 and 104 in the plane o the composite surface is shown. The fibers 102 run in

direction perpendicular to the fibers 104. Resins with high moduli will give composites with high compressive strength. The polymers of the present invention can be used to form composites by any of the established techniques, such as solution or powder impregnating

(prepregging) fiber tows, yarns, tapes and fabrics, followed by lay-up of the prepregs to the desired shape with a mold or form, and consolidating the composite by application of heat and pressure. Additives may be used as is known in the art including mold releases, anti- oxidants, curing agents, particulates, tougheners and the like.

Non limiting examples of additives which may be used with rigid-rod or segmented rigid-rod polyphenylenes are: adhesion promoters, antioxidants, carbon black, carbon fibers, compatibilizers, curing agents, dyes, fire retardants, glass fibers, lubricants, metal particles, mold release agents, pigments, plasticizers, rubbers, silica, smoke retardants, tougheners, UV absorbers, and the like.

The rigid-rod and segmented rigid-rod polymers of the present invention .may be used as additives to modify the properties of other polymers and compositions. Relatively small amounts of the polymers of the present invention will significantly increase the mechanical properties of flexible polymers. Addition of about 5% of the polymer 1 to a blend of polystyrene and polyphenylene oxide increases the tensile modulus by about 50%. The polyphenylenes of the present invention may be added to any other polymer. The degree of improvement of mechanical properties will depend on the properties of th other polymer without the added polyphenylene, on th amount of polyphenylene used, on the degree to which th polyphenylene is soluble in the other polymer, and on th amounts and types of additives or compatibilizers.

In general, polymers of differing types do not mix. There are many exceptions to this rule and many pairs o

completely miscible polymers are known. For most of these miscible polymers specific interactions result in a negative heat of mixing, for example, hydrogen bonding, or ionic interactions. Polymer pairs which are not miscible can often be made miscible by addition of a third polymer, typically a low MW copolymer having segments similar to the polymers to be blended. Use of these and other types of compatibilizers are known in the art. These techniques may be applied to the rigid-rod and segmented rigid-rod polyphenylenes of the present invention to enhance their utility as additives. Thus a copolymer having segments which interact strongly with a rigid-rod polyphenylene as well as segments which interact strongly with a secon polymer will act as a compatibilizer for the two. Smalle molecules such as NMP, triphenylphosphate, an diphenylether will also aid compatibility by solvating th polyphenylenes of the present invention. It will also b apparent to one skilled in the art that the particula side group on the rigid-rod or segmented rigid-ro polyphenylene will strongly influence its ability t blend. In general the side group should be chosen so tha there is a negative heat of mixing between the side grou and the polymer in which it must mix. It should also b apparent that complete miscibility is not always required. Blending often results in mixing on a microscopic, but no molecular, level. Such blends will have propertie different than the pure polymers and are often desirable Even blends with macroscopic phases may have utility an may be considered another form of composite. Rigid-rod and segmented rigid-rod polyphenylenes wil be particularly useful as additives for flame retardants smoke retardants, tougheners, or to control or enhanc creep resistance, coefficient of thermal expansion viscosity, modulus, tensile strength, hardness, moistur resistance, gas permeability, and abrasion resistance.

GENERAL PROCEDURES

1. 2,5 - dichlorobenzoyl-containing compounds A wide variety -of 2,5-dichlorobenzoyl-containing compounds (e.g. 2,5-dichlorobenzophenones and 2,5- dichlorobenzamides) can be readily prepared from 2,5- dichlorobenzoylchloride. Pure2,5-dichlorobenzoylchloride is obtained by vacuum distillation of the mixture obtained from the reaction of commercially available 2,5- dichlorobenzoic acid with a slight excess of thionyl chloride in refluxing toluene. 2,5-dichlorobenzophenones (e.g. 2,5-dichlorobenzophenone, 2,5-dichloro-4*- methylbenzophenone, 2,5-dichloro-4'-methoxybenzophenone, and 2,5-dichloro-4'-phenoxybenzophenone) are prepared by the Friedel-Crafts benzoylations of an excess of benzene or substituted benzenes (e.g. toluene, anisole, or diphenyl ether, respectively) with 2,5-dichlorobenzoylchloride at 0-5°C using 2-3 mole equivalents of aluminum chloride as a catalyst. The solid products obtained upon quenching with water are purified by recrystallization from toluene/hexanes. 2,5-dichlorobenzoylmorpholine and 2,5-dichloro- benzoylpiperidine are prepared from the reaction of 2,5-dichloro-benzoylchloride and either morpholine or piperidine, respectively, in toluene with pyridine added to trap the hydrogen chloride that is evolved. After washing away the pyridinium salt and any excess amine, the product is crystallized from the toluene solution.

2. Activated Zinc Powder

Activated zinc powder is obtained after 2-3 washings of commercially available 325 mesh zinc dust with 1 molar hydrogen chloride in diethyl ether (anhydrous) and drying in vacuo or under inert atmosphere for several hours a about 100-120°C. The resulting powder should be sifted

(e.g. a 150 mesh sieve seems to be satisfactory) , to remove the larger clumps that sometimes form, to assur

high activity. This material should be used immediatel or stored under an inert atmosphere away from oxygen an moisture.

The following specific examples are illustrative of th present invention, but are not considered limiting thereo in any way.

Example 1 Poly-1,4-(benzoylphenylene) Anhydrous bis(triphenylphosphine) nickel(II) chlorid (34.7 g; 53 mmole) , triphenylphosphine (166.6 g; 74 mole) , sodium iodide (34.6 g, 231 mmole), and 325 mes activated zinc powder (181.8 g, 2.8 mole) were weighe into a bottle under an inert atmosphere and added to a oven dried 12-liter flask, containing 1.6 liters o anhydrous N-methylpyrrolidinone (NMP) , against a vigorou nitrogen counterflow. This mixture was stirred for abou 15 minutes, leading to a deep-red coloration. Soli 2,5-dichlorobenzophenone and another 0.8 liters o anhydrous NMP were then added to the flask. After a initial slight endotherm (due to dissolution of monomer) the temperature of the vigorously stirred reaction mixtur warmed to about 60°C over 30 minutes and was held the (60-65°C) by use of a cooling bath. After stirring for additional 10-15 minutes, the viscosity of the reacti mixture increased drastically and stirring was stoppe

After heating this mixture for several days at 65°C, t resulting viscous solution was poured into 10 L of 1 mol hydrochloric acid in ethanol to dissolve the excess zi metal and to precipitate the macromonomer: Th suspension was filtered and the precipitate triturat with acetone and dried to afford 283 g (85% yield) of fine pale-yellow powder.

The sample was found to have an intrinsic viscosity 7.2 dL/g in 0.05 molar lithium bromide in NMP at 40° GPC analysis indicated a weight average molecular weigh relative to narrow polydispersity polystyrene standard Of 550,000-600,000.

Example 2 Polv-1,4-f4'-phenoxybenzoylphenylene) 2,5-Dichloro-4'-phenoxybenzophenone

To a 22L open-mouth round bottom flask fitted with a three-necked flange head, a mechanical stirrer, a nitrogen inlet and an outlet connected to a HCI scrubbing tower was added 2,5-dichlorobenzoic chloride (4500g, 21.5mol) and phenyl ether (5489g, 32.3mol). The solution was cooled in ice to 5°C under stirring and aluminum chloride (3700g, 27.8mol) was added slowly. After about 300g aluminum chloride was added, the solution started to foam violently. The rest was added carefully over about 10 min. On several occasions, the stirring had to be stopped to control the foaming. The temperature of the reaction mixture was about 35°C after the addition. The mixture was then stirred for about 30 min. and poured into about 20 gallon of ice water. The large ^' reddish mass was dissolved by adding about 12L of methylene chloride and stirring. The organic layer was separated and the aqueous layer was extracted with some methylene chloride. After methylene chloride was removed from the combined organic layer by distillation, the residue was recrystallize twice from cyclohexane (2xl0L) , washed with cooled hexane, air dried and then vacuum dried to afford 5387g monome (73%) . The mother liquor was kept for later recovery of remaining product.

Polv-1,4-(4'-phenoxybenzoylphenylene)

To a 12L open-mouth round bottom flask equipped with flange head, an air driven stirrer, a thermowell with thermocouple, and a nitrogen purge line, was added unde nitrogen bis(triphenylphosphine)nickel(II) chlorid

(58.2g, 88.9mmol), sodium iodide (54.7g, 365mmol) , triphenylphosphine (279.3g, 1065mmol) , 325mesh activate zinc dust (239.5g, 3663mmol) and anhydrou

N-methylpyrrolidinone (NMP) (3400ml) . The solution wa stirred and heated with a hot air gun to 40°C. Th

monomer 2,5-dichloro-4 '-phenoxybenzophenone (935g, 2725mmol) was added. The temperature dropped to 36.3°C and then climbed to about 65°C when an ice water bath was used to control the temperature below 86°C. After abou 15 min. the mixture became viscous. After 17 min. th solution became very thick and the stirring was stopped. The reaction mixture was allowed to come to roo temperature and was left to stand overnight. The nex morning the reaction mixture was coagulated into a acetone bath and ground up in a blender. The crud polymer was then stirred for several days in 1 mola hydrochloric acid in ethanol to remove the excess zin metal. The polymer was collected by filtration, washe with water and acetone and dissolved in 16L of methylen chloride. The solution was filtered through 10 u polypropylene membrane with the aid of celite, coagulate in the same volume of acetone, filtered, extracted wit acetone for three days and dried to 3afford 700g pal yellow polymer (94%) . GPC analysis showed a weigh average molecular weight of 653,000 with th polydispersity being 1.97, relative to polystyren standard.

Example 3 Polv-l,4-f2-r2-(2-methoxyethoxy.ethoxy1ethoχy carbonyl) henylene

2-r2-(2-Methoxyethoxy)ethoxy]ethyl 2 ,5-dichloro benzoate fTriethyleneglvcol 2,5-dichlorobenzoate)

To a round bottom flask fitted with a Dean-Steak wate separation apparatus, a magnetic stirrer and a condense were added 2,5-dichlorobenzoic acid (20g, O.llmol) triethylene glycol monomethylether (30ml, 0.17mol) concentrated sulfurie acid (0.4ml) and benzene (100ml) The mixture was refluxed for 3 days and about 1.8ml o water was collected. The solution was cooled to roo temperature and the solvent was removed on a rotar evaporator. The residue was diluted with ether and washe

with diluted aqueous sodium bicarbonate, washed with brine, and dried with magnesium sulfate. The liquid obtained after the removal of solvent was purified by filtration through about 5g of basic alumina, with methylene chloride as the eluent. The fraction, after distillation of solvent, was dried under vacuum overnight with stirring to afford 30.8g of pure ester (88%) .

Poly-1,4- (2-T2-(2-methoxyethoxy) ethoxy1ethoxycar- bony!)phenylene Into a 100 ml round bottom flask containing NMP (7.5 ml) were weighted in a glove box anhydrous nickel(II) chloride (30 mg, 0.23 mmol) , sodium iodide (125 mg, 0.83 mmol), triphenylphosphine (0.5g, 1.91 mmol), activated zinc dust (0.65 g, 10.16 mmol). This mixture was stirred with a magnetic stirrer for 40 min. at 50°C, leading to a deep red solution. Monomethylated triethyleneglycol 2,5- dichlorobenzoate (2.8 g, 7.95 mmol) was added as a neat liquid with a syringe. The mixture was stirred at this temperature for 3 days, resulting a viscous solution. Ethanol (100 ml) was added. A suspension was obtained after stirring. It became a clear and almost colorless solution when 10 ml of 36% hydrochloric acid was added. The solution then was neutralized with diluted aqueous sodium hydroxide. The resulting suspension containing gel-like polymer was extracted with methylene chloride.

The organic layer was filtered and concentrated. The polymer was precipitated with ethanol, separated by using a centrifuge and dried under vacuum. A white, gum-like solid was obtained (1.48 g, 67%). The weight average molecular weight, relative to polystyrene standard, was

116,000 according to GPC analysis.

Example 4

Poly-1,4- (3'-methylbenzoylphenylene)

2,5-Dichloro-3'-methylbenzophenone

A mixture of m-toluoyl chloride (22g, 0.17mol) and 1,4 dichlorobenzene (120g, 0.82mol) was heated to lOOoC in flask. Aluminum chloride (60g, 0.45mol) was added in on portion. Hydrogen chloride started to evolve from th solution. The mixture was heated to 170°C in 30 min. a stirred at this temperature for 3 hours. The resulti brownish solution was cooled to about 80°C and poured on ice. Ether (50ml) was added. The organic layer wa separated and distilled under vacuum after the removal o ether. The residue from distillation was recrystalliz twice from hexane to give 20g of white crystals (53%) .

Polv-l,4- (3'-methylbenzoyl) henylene

Anhydrous nickel(II) chloride (60mg, 0.47mmol), sodi iodide (175mg, 1.17mmol), triphenylphosphine (0.75

2.86mmol), activated zinc dust (2.3g, 35.9mmol) we weighed in a glove box into a 100ml round bottom fla containing NMP (8ml) . This mixture was stirred with magnetic stirrer for 30min. at 50°C, leading to a deep r solution. A solution of 2,5-dichloro-3 ' methylbenzophenone (2.6g, 9.85mmol) in NMP (7ml) w added. A viscous solution was obtained after stirring f 40 minutes. The mixture was kept at this temperature f another 10 hours and then at 65°C for another 3 day Ethanol was added to the reaction mixture. The solid w moved into a blender, ground into small pieces and th stirred with 50ml of 1 molar hydrochloric acid in ethan for 2 hours. The off-white solid was filtered and stirr with acetone overnight. Filtration and vacuum drying ga 1.62g off-white powder (85%). The weight avera molecular weight, relative to polystyrene standard, w 139,000 according to GPC analysis.

EXAMPLE 5 Melt extrusion of Poly -1.4-(4'-phenoxybenzoylphenylen

Poly -l,4-(4'-phenoxybenzoylpheneylene) provided

accordance with Example 2 is dried to constant weight in a vacuum oven at 170 °C. The dry polymer is loaded into the hopper of a twin screw extruder with inlet and barrel temperature set to 270 °C. In a first extrusion run, the extruder is fitted with a heated die having a 50 cm by 2 mm slit. The extruded sheet is air cooled and cut into 50 cm lengths. The sheet stock is thermoformed by pressing between shaped platens of a steel mold at 250 °C and 500 psi. In a second extrusion run, the extruder is fitted with a heated die having a 10 cm by 0.2 mm slit. The extruded film is passed through a train of heated rollers and then abruptly accelerated between two rollers of different speeds to stretch the film by about 500%. Addition heat may be applied to keep the film above its T _g (about 160

°C) by radiant heating. The stretched film is annealed and cooled on a further roller train and collected as a continuous roll.

In a third extrusion run, the extruder is fitted with a die having 500 spinnerets, each 200 microns in diameter at the exit. The polymer is extruded through the die and the multifila ents allowed to air cool before being collected on a windup bobbin.

In a fourth extrusion run, the extruder is fitted with a die having 200 spinnerets, each 400 in diameter microns at the exit. The extruded filaments are pulled away from the exit at high velocity resulting in a draw ratio of about 12. The oriented fiber is collected on a windup bobbin. In a fifth extrusion run, the extruder is fitted wit a die suitable for extrusion of 1/2 inch pipe having 1/1 inch wall thickness. The pipe is cut into 4 foot lengths.

Example 6 Production of Angle Stock of polv-1,4- (A'-phenoxybenzoylphenylene^

A blend of poly-l,4-(4'-phenoxybenzoylphenylene)

provided in accordance with Example 2, 200 g, polystyrene 1000 g, and triphenylphosphate, 100 g is loaded into th hopper of a single screw extruder. The blend is extrude through a die having an L shaped slit 1 inch by 1 inch b 3/16 inch to produce angle stock.

Example 7 Production of Fibers of polv-1.4-(4'-phenoxybenzoylphenylene) 50 g of poly-1,4-(4'-phenoxybenzoylphenylene) provide in accordance with Example 2 is dissolved in a mixture o NMP, 25 ml, and methylene chloride, 425 ml by stirring fo 48 hours. The viscous solution is pumped through a 0.2 m orifice. In the first run, the orifice is submerged at one en of a one meter trough containing 95% ethanol. The solutio coagulates as it is injected into the ethanol. Th coagulated polymer is manually pulled through the troug to the end opposite the orifice where it is threade through rollers and attached to a take up spool. The spee of the take up spool is regulated to provide a constan tension to the fiber.

In the second run, the orifice is held one centimet from the surface at one end of a trough containing 95 ethanol. The solution is forced through the orifice as fine jet directed downward. The solution coagulates as impinges on the ethanol. The coagulating fiber is f around a roller and across the trough to the opposite e where it is collected on a constant tension take up rol Example 8

Coating a Silicon Wafer with polv-1.4- (A'-phenoxybenzoylphenylene^

50 g is of poly-1,4-(4'-phenoxybenzoylphenylen dissolved in a mixture of NMP, 25 ml, and methyle chloride 425 ml by stirring for 48 hours. A 4" silic wafer is coated with a thin film of poly-l,4-(4 phenoxybenzoylphenylene) by spin coating the solution

300 rpm for 15 sec followed by 1500 rpm for 60 sec. The coated wafer is further dried in a 100°C vacuum oven for 6 hrs.

Example 9 Melt Spray Coating with polv-1,4-f4'-phenoxybenzoylphenylene)

A blend of poly-1,4-(4'-phenoxybenzoylphenylene) 50 g, and polystyrene, 400 g are loaded into the heated reservoir of a spray gun. The molten blend is forced by compressed nitrogen through the gun nozzle to form a coarse spray. The spray is directed such that a metal part is uniformly covered with polymer. The coated part may be heated further in an oven to level the polymer coating. Example 10

Powder Prepregging with polv-1.4- ( '-phenoxybenzoylphenylene^

Poly-1,4-(4'-phenoxybenzoylphenylene) provided in accordance with Example 2 is prepared as a powder having average particle size of about 10 microns. The powder is placed at the bottom of a closed chamber having a means to stir the powder. . Carbon fiber tow is drawn through the chamber whereupon the stirred powder forms a dust cloud which adheres to the carbon fibers. On leaving the powder chamber the coated carbon fibers then pass through a 150°C oven to fix the polymer powder. The resulting prepreg may be used to form composites by further forming and processing under heat and pressure.

Example 11

Composite Fabrication with Prepreg from polv-1,4- ( '-phenoxybenzoylphenylene)

The prepreg of Example 10 is wound onto a cylindrica tool. Heat and pressure are applied as the prepreg to contacts the cylinder surface so as to consolidate th polymer powder. The cylinder is completely wound with si layers of prepreg. During this operation the new layer

are bonded to the underlying layers with local applicatio of heat and pressure. This on-line consolidation allow large parts to be fabricated without the use of a autoclave.

Example 12 Comingled Filament Winding with poly-1,4-(4'-phenoxybenzoylphenylene) Fibers

The fiber tow of the fourth extrusion run of Example is co-mingled with carbon fiber tow having 500 filament and wound on a bobbin. The resulting tow is used t filament wind a nosecone. The nosecone and tool ar placed in a 200°C oven for 1 hour to consolidate t polymer filaments.

Example 13 Pultrusion with Rigid-Rod Polyphenylene Fibers

The fiber tow of the fourth extrusion run of Example is continuously pulled through a polyetheretherketone me and co-extruded through a die to form ribbed panels.

Example 14 Blow Molding of a polycarbonate polv-1,4-(4'-phenoxybenzoylphenylene) Blend A 90:10 blend of polycarbonate and poly-l,4-(4 ' phenoxybenzoylphenylene) provided in accordance wi Example 2 is used in an injection blow molding machine produce 1 liter bottles. In the process a parison formed by an injection molding operation, the parison then moved to a mold and inflated to fill the mold. Aft cooling the finished bottle is removed from the mold.

Example 15 Polv-1.4- ( A'-phenoxybenzoylphenylene) Anhydrous bis(triphenylphosphine) nickel(II) chlori

(102 g; 0.16 mole), triphenylphosphine (408 g; 1.56 mole sodium iodide (96 g, 0.64 mole), and 325 mesh activat

zinc powder (420 g, 6.42 mole) were weighed into a bottle under an inert atmosphere and added to an oven dried 22- liter flask, containing 4 liters of anhydrous NMP, against a vigorous nitrogen counterflow. This mixture was stirred for about 15 minutes, leading to a deep-red coloration.

Solid 2,5-dichloro-4'-phenoxy-benzophenone and another 2 liters of anhydrous NMP were then added to the flask. After an initial slight endotherm (due to dissolution of monomer) , the temperature of the vigorously stirred reaction mixture warmed to about 85°C over 15-20 minutes and was held there by use of a cooling bath. After stirring for an additional 10-15 minutes, the viscosity of the reaction mixture increased drastically and stirring was stopped. After cooling the reaction mixture to room temperature overnight, the resulting viscous solution was coagulated into 25 L of 1 molar hydrochloric acid in ethanol to dissolve the excess zinc metal and to precipitate the polymer. This suspension was filtered, and the precipitate was continuously extracted with ethanol and then with acetone and dried.

To achieve high purity, the crude polymer was dissolved in about 35 liters of NMP, pressure filtered through 1.2 micron (nominal) polypropylene fiber filters, coagulated into about 70 liters of acetone, continuously extracted with acetone, and dried to afford 1,186 g (91% yield) of a fine pale-yellow powder.

The sample was found to have an intrinsic viscosity o 5.0 dL/g in 0.05 molar lithium bromide in NMP at 40°C. GPC analysis indicated a weight average molecular weight, relative to narrow polydispersity polystyrene standards, of 450,000-500,000.

EXAMPLE 16 Copolv- -f 1 , 4 - f benzoylphenylene) V --T 1 , 3 -phenylene Anhydrous bis (triphenylphosphine) nickel (II) chlorid

(10 g; 15 mmole) , triphenylphosphine ( 50 g; 0. 19 mole) , sodium iodide (12 g, 80 mmole) , and 325 mesh activate

zinc powder (60 g, 0.92 mole) were weighed into a bottl under an inert atmosphere and added to an oven dried 2 liter flask, containing 800 milliliters of anhydrous NMP against a vigorous nitrogen counterflow. This mixture wa stirred for about 15 minutes, leading to a deep-re coloration. A mixture of 2,5-dichlorobenzophenone (127 g 0.51 mole) and 1,3-dichlorobenzene (11 ml; 96 mmole) wa then added to the flask. After an initial sligh endotherm (due to dissolution of monomer) , the temperatur of the vigorously stirred reaction mixture warmed to abou

80-85°C over 30 minutes. After stirring for an additiona 10-15 minutes, the viscosity of the reaction mixtur increased drastically and stirring was stopped. Afte cooling the reaction mixture to room temperatur overnight, the resulting viscous solution was poured int

6 L of 1 molar hydrochloric acid in ethanol to dissol the excess zinc metal and to precipitate the polyme This suspension was filtered and the precipitate w continuously extracted with ethanol and then with aceto and dried to afford 93 g (94% yield) of crude white resi

To achieve high purity, the crude polymer was dissolv in about 600 L of methylene chloride, pressure filter through 1.2 micron (nominal) polypropylene fiber filter coagulated into about 2 liters of acetone, continuous extracted with acetone, and dried to afford 92 g (9 yield) of a fine white powder.

The sample was found to have an intrinsic viscosity 1.75 dL/g in 0.05 molar lithium bromide in NMP at 40° GPC analysis indicated a weight average molecular weigh relative to narrow polydispersity polystyrene standard of 150,000-200,000. DSC analysis indicated a gla transition temperature of 167°C.

EXAMPLE 17 Copolv--fl,4- (benzoylphenylene) }--f1 , 4-phenylene

Anhydrous bis(triphenylphosphine) nickel(II) chlori (3.75 g; 5.7 mmole), triphenylphosphine (18 g; 68

mmole) , sodium chloride (2.0 g, 34.2 mmole), 325 mesh activated zinc powder (19.5 g, 298 mmole), and 250 L of anhydrous NMP were weighed into an oven dried 1-liter flask under an inert atmosphere. This mixture was stirred for about 15 minutes, leading to a deep-red coloration.

A mixture of 2,5-dichlorobenzophenone (45 g; 179 mmole) and 1,4-dichloro-benzene (2.95 g; 20 mmole) was then added to the flask. The temperature of the vigorously stirred reaction mixture was held at 60-70°C until the mixture thickened (about 30 minutes) . After cooling the reaction mixture to room temperature overnight, the resulting viscous solution was poured into 1.2 L of 1 molar hydrochloric acid in ethanol to dissolve the excess zinc metal and to precipitate the polymer. This suspension was filtered and the precipitate was washed with acetone and dried to afford crude resin.

To achieve high purity, the crude polymer was dissolved in about 1.5 L of NMP and coagulated into about 4 L of acetone, continuously extracted with acetone, and dried to afford 30 g (89% yield) of an off-white powder.

The sample was found to have an intrinsic viscosity of 4.9 dL/g in 0.05 molar lithium bromide in NMP at 40°C. GPC analysis indicated a weight average molecular weight, relative to narrow polydispersity polystyrene standards, of 346,000. DSC analysis indicated a glass transitio temperature of 167°C.

EXAMPLE 18 Preparation of Solvent Cast Thin Films of Rigid-Ro Polyparaphenylenes of Examples 1 and 2.

Two methods are preferred for the preparation of goo quality solvent cast films of the polymers provided i accordance with Examples 1 -and 2. All films are cast i a particle free, low humidity environment, preferably fro filtered polymer solutions.

(a) The first method involves casting from solution (about 1-15 weight percent, preferably about 3-7 weigh

percent) in chloroform, anisole, dimethylacetamide (DMAc) N-methylpyrrolidinone (NMP), or other suitable solvents The solvent is evaporated, if low boiling, or removed i a vacuum or convection oven, if high boiling. The films especially those thinner than about 1 mil, tend to b brittle but quite strong.

(b) A second method for preparing free-standing film involves casting from a solvent mixture of chloroform an NMP (generally containing about 1-10 volume percent NMP preferably about 1-2 volume percent) . Polyme concentrations typically range from about 1-15 weigh percent, preferably about 3-7 weight percent. Afte casting the film, the chloroform quickly evaporates leaving a highly NMP swollen (plasticized) but generall tack-free film. The remaining NMP can be easily remove by heating in an oven to form the final dry film, whic tends to be quite optically transparent and colorless Like those prepared from a single solvent, the completel dried films tend to be brittle but strong. The following film samples were prepared from batche of rigid-rod polyparaphenylenes in Examples 1 and 15 wit the specified intrinsic viscosities (related to molecula weight) according to the general procedures specifie above and the conditions listed:

The mechanical (tensile) properties of the resulti films (A-F) were measured in accordance with ASTM-D-8

standards. Standard test samples were prepared by carefully cutting the films to the desired size (approximately 6"x 0.5"x 0.001"). The films prepared by method (b) were more easily cut (i.e. without microcracking along the edge of the test strip) in their plasticized state. The average test results are presented below:

The film of Example 18 E is dried until it is approximately 5% by weight NMP. The NMP plasticized film is drawn through a set of rollers to give a draw ratio of 5 to 1. The oriented film may be further dried in vacuo at 100 °c.

EXAMPLE 20 Compression Molding of Rigid-Rod Polv-1.4-fbenzoyl¬ phenylene) _r Example 1 Material, and Polv-1.4-(4'- phenoxybenzoylphenylene) , Example 2 Material.

Coupons of the polymers provided in accordance with the procedures of Examples 1 and 2 can be compression molded at relatively moderate temperatures (200-400°C) and pressures (200-5,000 psi). Sometimes samples of the polymers of Examples l or 2 undergo darkening upon molding at these temperatures, but the properties do not seem to

be adversely affected. To obtain 2"x 2"x 0.1" panels of a batch of the polymer of Example 1 (with an intrinsic viscosity of 4.0 dL/g) or the polymer of Example 2 (wit an intrinsic viscosity of 5.0 dL/g), the mold cavity is filled with about 8.0 g of resin and placed into a hydraulic press preheated to the specified temperature. After holding the sample at the molding temperature an molding pressure for the specified molding time, th sample is cooled below at least about 100°C during th cooling time while retaining the molding pressure. Upo cooling to ambient temperature and removal from the mold, the following panels were obtained according to th specified conditions:

The mechanical (flexural) properties of the resultin panels (G-J) were measured in accordance with ASTM-D-79 standards. Standard test samples were prepared b carefully cutting the panels to the desired size (40mm 6 mm x 2.6 mm). The test results are presented below:

A free-standing film, K, sample of copoly-{l,4- benzoylphenylene) }-{l,3-phenylene} ([η] = 1.75 dL/g) was prepared by conventional casting techniques from a 5.0 % (wt/wt) solution in chloroform. After drying, the mechanical (tensile) properties of the film were measured according to ASTM-D-882 specifications. A molded coupon (2"x 2"x 0.1") , L, of copoly-{l,4-benzoylphenylene) }-{l,3- phenylene} was prepared by compression molding about 8.0 g of resin at 300°C and 1,250 psi pressure for 30 minutes and then cooling slowly (about 3 hours) to ambient temperature while maintaining pressure. The mechanical (flexural) properties of the coupons were measured according to ASTM-D-790 specifications; standard test samples were prepared by carefully cutting the coupons to the desired size (40 mm x 6 mm x 2.5 mm) . The following data was obtained for samples K and L:

Sample identi- Sample Measurement Strength Modulus Strain fication type Type (psi) (psi) %

EXAMPLE 22

Injection Molding of Rigid-Rod Poly-1 , A- ( ' - phenoxybenzoyl-phenylene)

Complex parts of the polymer provided in accordance with the process of Example 2 were injection molded by standard techniques at moderate temperatures (280°C) . Mechanical (flexural) properties were measured according to ASTM-D- 790 specifications and melt viscosity was measured at

280°C with a melt rheometer with a capillary geometry of 10 mm length and 1 mm diameter at a shear rate of 1,000/sec. The following data was obtained for injection molded strips of dimension 40 mm length x 6 mm width x 1 mm thickness (MD, machine direction, refers to specimens molded in the long direction (40 mm) to induce some orientation and TD, transverse direction, refers to specimens molded in the short direction (6 mm) to minimize any orientation) :

Blendsofpoly-l,4-(4'-phenoxy-benzoylphenylene) ([η]

= 5.5 dL/g in 0.05 M LiBr/NMP at 40°C) and polybutylen terephthalate (e.g. NOVADUR PBT from Mitsubishi Kase Corporation; [η] = 1.1 dL/g in 1/1 1,1,2,2

tetrachloroethane/phenol) were prepared by conventional melt extrusion and test samples (40 mm length x 6 mm width x 1 mm thickness) were obtained by injection molding ^* at 280°C. Relative to samples prepared from pure polybutylene terephthalate, the blend samples typically demonstrated better flexural strength and modulus (ASTM-D- 790) and shown below (MD, machine direction, refers to specimens molded in the long direction (40 mm) to induce some orientation and TD, transverse direction, refers to specimens molded in the short direction (6 mm) to minimize any orientation) :

The polymer blends were prepared in a small (50 g)

Brabender mixer (C.W. Brabender, Inc.; Hackensack, NJ) . The particular batch of poly-1, 4- (4 ' - phenoxybenzoylphenylene) used for these experiments possessed the following properties: [77] = 3.5 dL/g (0.05M LiBr/NMP at 40°C) ; M ^{5 0 ~~~} 275,000; T _g (DSC) = 143°C; and melt viscosity (at 300°C and 1,000/sec shear rate) = 4,100 poise. The mixer was preheated to the temperature

indicated below for the specified polymer to be blended with poly-1,4-(4'-phenoxybenzoylphenylene) , and the resin was added slowly and allowed to achieve uniform melt consistence over about 5 minutes. The poly-l,4-(4'- phenoxybenzoylphenylene) or a mixture of poly-l,4-(4'- phenoxybenzoylphenylene) and triphenylphosphate (TPP; used as a plasticizer to lower the melt viscosity of the polyparaphenylene) was then added. If the blend was not uniform after about 5 minutes of mixing, the temperature was increased to about 280-300°C for 5 minutes. The mixer was then cooled to 165°C, and the blend was removed and allowed to cool to room temperature. The following blends were prepared in this manner:

Polystyrene = HCC9100 from Hunter Chemical Co . ; Poly (phenylene oxide) = Noryl 731 from GE Plastics ; Nylon-6 (poly-e-caprolactam) = DYLARK 232 from ARCO Chemical .

Compression molded panels of the above blends were prepared for mechanical (tensile) testing according to ASTM-D-638 standards by molding at the temperature specif ied below at about 700 psi for 2 minutes and then cooling to room temperature . The glass transition temperatures (T _α ) were determined for the blends by dynamic mechanical thermal analysis (DMTA) of the compression molded parts . Specimens appropriate for DMTA and mechanical testing (size approximately 6"x 0.5"x 0. 1" )

were prepared from the molded panels by using a band-saw and/or a router. The following data was obtained:

The polymer blends were prepared in a small (50 g) Brabender mixer (C.W. Brabender, Inc.; Hackensack, NJ) . The particular batch of poly-1,4-(benzoylphenylene) used for these experiments possessed the following properties: [ij] = 3.5 dL/g (0.05M LiBr/NMP at 40°C) ; M^ ^{3 0} = 300,000; and melt viscosity (at 300°C and 100/sec shear rate) = 27,000 poise. The mixer was preheated to the temperature indicated below for the specified polymer to be blended with poly-1,4-(benzoylphenylene) , and the resin was added slowly and allowed to achieve uniform melt consistence over about 5 minutes. The poly-1, -(benzoylphenylene) or a mixture of poly-1,4-(benzoylphenylene) and triphenylphosphate (TPP; used as a plasticizer to lower the melt viscosity of the polyparaphenylene) was then added. If the blend was not uniform after about 5 minutes of mixing, the temperature was increased to about 280- 300°C for 5 minutes. The mixer was then cooled to 165°C, and the blend was removed and allowed to cool to room

Polystyrene = HCC9100 from Hunter Chemical Co.; Poly(phenylene oxide = Noryl 731 from GE Plastics; Polypropylene = Profax 6523 fro Himont; Polyethylene (high density) = # 8640 from Chevron.

Compression molded panels of the above blends wer prepared for mechanical (tensile) testing according t ASTM-D-638 standards by molding at the temperatur specified below at about 700 psi for 2 minutes and the cooling to room temperature. The glass transitio temperatures (T _g ) were determined for the blends b dynamic mechanical thermal analysis (DMTA) of th compression molded parts. Specimens appropriate for DMT and mechanical testing (size approximately 6"x 0.5"x 0.1" were prepared from the molded panels by using a band-sa and/or a router. The following data was obtained:

The polymer blends were prepared by mixing solutions of each polymer in chloroform or a solvent mixture comprised of 90 % (vol/vol) chloroform and 10 % (vol/vol) NMP in proper proportion to achieve the compositions specified below. The particular batch of poly-1,4- (benzoylphenylene) used for these experiments possessed the following properties: [η] = 3.5 dL/g (0.05M LiBr/NMP at 40°C) ; M ^{3 0} = 300,000; and melt viscosity (at 300°C and 100/sec shear rate) = 27,000 poise. The polystyrene was obtained from Hunter Chemical Co. (HCC9100) . The blended resins were rapidly precipitated by pouring the co-solutions into methanol (3 volumes relative to the volume of polymer co-solution) . The precipitate was filtered, washed with additional methanol, and dried under vacuum for 24 hours at 70°C. Compression molded panels of these blends were prepared for mechanical (tensile)

testing according to ASTM-D-638 standards by molding at 175°C at about 700 psi for 2 minutes and then cooling to room temperature. The glass transition temperatures (T _g ) were determined for the blends by dynamic mechanical thermal analysis (DMTA) of the compression molded parts. Specimens appropriate for DMTA and mechanical testing (size approximately 6"x 0.5"x 0.1") were prepared from the molded panels by using a band-saw and/or a router. The following data was obtained:

EXAMPLE 27 Preparation of Blends of Polv-1,4-(4 ^/ -phenoxybenzoyl¬ phenylene) with Polycarbonate by Solution Mixing.

The polymer blends were prepared by mixing solutions of each polymer in chloroform in proper proportion to achieve the compositions specified below. The particular batch of poly-1,4-(benzoylphenylene) used for these experiments possessed the following properties: [η] = 5.2 dL/g (0.05M LiBr/NMP at 40°C) and M _W ^GPC = 450,000. The polycarbonate was obtained from Mitsubishi Kasei Corporation (NOVAREX polycarbonate) . The blended solutions were then cast onto a glass plate and dried rapidly to afford transparent free-standing thin film samples. The following mechanical

(tensile) properties were measured according to ASTM-D-882 specifications:

Sample Polypara- Tensile Tensile Identi- phenylene Strength Modulus Elongation fication (wt %) (psi) (psi) (%)

7 , 200 3 . 2 X 10- 8.6 7 , 800 3 . 9 X 10- 3.4

7 , 100 5 . 7 X lO 1.6

17 , 400 7 . 0 X 10 ⁵ 2.0

18 , 100 11. 3 X 10 ^! 1.9 21 , 000 15 . 6 X 10 ^J 1.8

EXAMPLE 28 Solutions containing 1.5 to 3 wt.% of poly-1,4- (benzoylphenylene) provided in accordance with Example 1 in Epo ik R140 (Mitsui) were prepared by stirring the polymer and the epoxy resin at 100-140°C. The resulting solutions were almost colorless. Both 1.5 and 3 wt% solutions were very viscous at room temperature, however, the viscosity of the solution dropped sharply with warming. To about lg of solution of the polymer of Example 1 in Epomik R140 was added 6-12 drops of ethylenediamine (EDA) . The resulting solution was mixed with a spatula until a homogeneous solution was obtained. The mixture was left to sit at room temperature to cure. Curing took from a few hours to two days depending on the amount of EDA. In all cases, a hard transparent mass was obtained. If the polymer mixture with EDA was heated to about 70°C a very exothermic reaction occurred. The resulting cured polymer blend in this case was slightly turbid. Curing was also successful when a small amount of NMP was used as plasticizer.

Example 29 Determination of the Relative Coupling Reactivities of

Monohaloarene Model Compounds Using Nickel-

Triarylphosphine Catalysts.

A mixture of 50 mg (0.39 mmole) of anhydrous nickel chloride, 175 mg (1.17 mmole) of sodium iodide, 750 mg (2.86 mmole) of triphenylphosphine, 1.0 g (15.30 mmole) of activated zinc powder, 500 mg (2.17 mmole) of ortho- terphenyl (used as an internal standard for chromatographic analysis) , and 7 ml of NMP was placed into a flask under an inert atmosphere and heated at 50°C for 10-15 minutes until the mixture achieved a deep red coloration, indicative of an activated catalyst solution. Then approximately 19.3 mmole (50 mole equivalents vs. anhydrous nickel chloride) of the desired monohaloarene model compound was added to the flask. The course of the reaction waε then followed by monitoring the disappearance of the monohaloarene model compound by standard quantitative gas chromatographic (GC) or high pressure liquid chromatographic (HPLC) techniques. Two simple approaches were utilized to quantify the reactivities of the model compounds: (1) extent of reaction (conversion) of the model compound after two hours and (2) the amount of time required to achieve at least 90% conversion. The first technique requires fewer measurements but can be strongly affected if there is any initiation period. The following data was obtained by the above technique for the specified monohaloarene model compounds:

trifluoride 3-chlorobenzo- > 95 < 1 hr trifluoride 2-chlorobenzoyl- 5-10 > 40 hrs morpholine

A mixture of o-toluoyl chloride (22g, 0.17mol) and 1,4-dichlorobenzene (120g, 0.82mol) was heated to 100°C in a flask. Aluminum chloride (60g, 0.45mol) was added in one portion. The mixture was heated to 170°C in 30 min and stirred at this temperature for 3 hours. The resulting brownish solution was cooled to about 80°C and poured onto ice. Ether (50ml) was added. The organic layer was separated and distilled under vacuum after the removal of ether. The residue from distillation was recrystallized twice from hexane to give 16g of white crystals (36%) .

Polv-l,4- (2 '-methylbenzoylphenylene)

Anhydrous nickel(II) chloride (60mg, 0.47mmol), sodium iodide (175mg, 1.17mmol), triphenylphosphine (0.75g, 2.86mmol), activated zinc dust (2.3g, 35.9mmol) were weighted in a glove box into a 100ml round bottom flask containing NMP (8ml) . This mixture was stirred with a magnetic stirrer for 30 min at 50°C, leading to a deep red solution. A solution of 2.5-Dichloro-2'- methylbenzophenone (lOmmol) in NMP (7ml) was added. Stirring was continued for about 40 minutes until a

viscous solution was obtained. The mixture was kept at 65°C for another 2-3 days. Ethanol was added to the reaction mixture. The solid was moved into a blender, ground into small pieces and then stirred with 50ml of 1 molar hydrochloric acid in ethanol for 2 hours. The off- white solid was filtered and stirred with acetone overnight. Filtration and vacuum drying gave off-white or pale yellow powder. The weight average molecular weight relative to polystyrene standard according to GPC analysis was 70,000.

Example 31 ΕOlv-l . A- ( 2 ' ,5'-dimethylbenzoylphenylene)

2,5-Dichloro-2 ' ,5'-dimethylbenzophenone To p-xylene (120ml, 0.98mol) was added aluminum chloride (32g, 0.24mol) at room temperature. To this mixture 2,5-dichlorobenzoyl chloride (30g, 0.14mol) was added slowly. The reaction was exothermic and hydrogen chloride evolved from the reddish solution. After the addition, the mixture was stirred for lOmin and then hydrolysed by slow addition of water. The aqueous layer was extracted with ether. The organic layer was combined with ethereal extract and washed with water, saturated sodium bicarbonate, brine, respectively, and then dried with magnesium sulfate. After the removal of solvent, the residue was recrystallized from methanol twice and then from hexane to give 36.8g (92%) crystals (mp 58-61°C) . Polv-l.4-(2 ' .5'-dimethylbenzoylphenylene) Anhydrous nickel(II) chloride (60mg, 0.47mmol) , sodium iodide (175mg, 1.17mmol), triphenylphosphine

(0.75g, 2.86mmol), activated zinc dust (2.3g, 35.9mmol) were weighted in a glove box into a 100ml round bottom flask containing NMP (8ml) . This mixture was stirred with a magnetic stirrer for 30 min at 50°C, leading to a deep red solution. A solution of 2.5-Dichloro-2 ^/ .5 ' - dimethylbenzophenone (lOmmol) in NMP (7ml) was added. Stirring was continued for about 40 minutes until a

viscous solution was obtained. The mixture was kept at 65°C for another 2-3 days. Ethanol was added to the reaction mixture. The solid was moved into a blender, ground into small pieces and then stirred with 50ml of 1 molar hydrochloric acid in ethanol for 2 hours. The off- white solid was filtered and stirred with acetone overnight. Filtration and vacuum drying gave off-white or pale yellow powder. The weight average molecular weight relative to polystyrene standard was 50,000 according to GPC analysis.

Example 32 Poly-1,4- (2-(2-pyrrolidinon-l-yl)ethoxycarbonylphenylene 2-(2-Pyrrolidinon-l-yl)ethyl 2,5-dichlorobenzoate

A mixture of 2 ,5-dichlorobenzoic acid (20g, O.llmol) , l-(2-hydroxyethyl-2-pyrrolidinone (27g, 0.22mol) in benzene (100ml) was refluxed in the presence of 1ml of concentrate sulfurie acid for 24 hours. About 2.2ml of water was collected. The mixture was cooled and washed with aqueous sodium bicarbonate and water, respectively and evaporated. The residue was purified by recrystallization from hexane and ethyl acetate to give the esters as white crystals (lOg, 32%) .

Polv-l.4-f2-(2-pyrrolidinon-l-yl) ethoxycarbonyl- phenylene) Anhydrous nickel(II) chloride (60mg, 0.47mmol) , sodium iodide (175mg, 1.17mmol), triphenylphosphine (0.75g, 2.86mmol), activated zinc dust (2.3g, 35.9mmol) were weighted in a glove box into a 100ml round bottom flask containing NMP (8ml) . This mixture was stirred with a magnetic stirrer for 30 min at 50°C, leading to a deep red solution. A solution of 2-(2-Pyrrolidinon-l-yl)ethyl 2,5-dichlorobenzoate (lOmmol) in NMP (7ml) was added. Stirring was continued for about one week and a viscous solution was obtained. The mixture was kept at 65°C for another 2-3 days. Ethanol was added to the reaction mixture. The solid was moved into a blender, ground into small pieces and then stirred with 50ml of 1 molar

hydrochloric acid in ethanol for 2 hours. The off-white solid was filtered and stirred with acetone overnight. Filtration and vacuum drying gave off-white or pale yellow powder. The polymer has structure

I with R _j _= -C0 ₂ CH ₂ CH ₂ NCOCH ₂ CH ₂ CH ₂ , and R ₂ -R ₄ =H The weight average molecular weight, relative to polystyrene standard according to GPC analysis was 72,000.

Example 33

Polv-l.4-(4'-(2-phenoxyethoxy)benzoylphenylene) 2.5-Dichloro-4 ' - (2-phenoxyethoxy)benzophenone

To a suspension of 1,2-diphenoxyethane (25g, O.llmol), aluminum chloride (14g, O.llmol) in chlorobenzene (400ml) was added slowly 2,5-dichlorobenzoyl chloride (9.8g, 0.05mol) at OoC. After the addition, the mixture was stirred for another 20 minutes and worked up as usual. After the removal of solvent, the residue was purified by chromatography on silica gel and recrystallization from cyclohexane to give 9g pure ketone

(50%) .

Poly-1,4-(4'-(2-phenoxyethoχy)benzoylphenylene) Anhydrous nickel(II) chloride (60mg, 0.47mmol) , sodium iodide (175mg, 1.17mmol), triphenylphosphine (0.75g, 2.86mmol), activated zinc dust (2.3g, 35.9mmol) were weighted in a glove box into a 100ml round bottom flask containing NMP (8ml) . This mixture was stirred with a magnetic stirrer for 30 min at 50°C, leading to a deep red solution. A solution of 2.5-Dichloro-4 ' - (2- phenoxyethoxy) -benzophenone (lOmmol) in NMP (7ml) was added. Stirring was continued until a viscous solution was obtained, about 3 hours. The mixture was kept at 65°C for another 2-3 days. Ethanol was added to the reaction mixture. The solid was moved into a blender, ground into small pieces and then stirred with 50ml of 1 molar hydrochloric acid in ethanol for 2 hours. The off-white solid was filtered and stirred with acetone overnight.

Filtration and vacuum drying gave off-white or pale yellow powder. The weight average molecular weight relative to polystyrene standard was 218,000 by GPC analysis.

The above descriptions of exemplary embodiments of processes for producing rigid-rod and segmented rigid-rod polymers, and the rigid-rod and segmented rigid-rod polymers produced by the processes, are for illustrative purposes. Because of variations which will be apparent to those skilled in the art, the present invention is not intended to be limited to the particular embodiments described above. The scope of the invention is defined in the following claims.