COATING COMPOSITION CONTAINING BRANCHED COPOLYETHER

POLYOL POLYMER FIELD OF INVENTION

[01] The present invention is directed to a coating composition comprising a branched copolyether polyol polymer derived from 1 ,3-propanediol. This disclosure is particularly directed to a coating composition having components derived from bio-resourced 1 ,3-propanediol.

BACKGROUND OF INVENTION

[02] Coating compositions are utilized to form coatings, such as, for example, primers, basecoats and clearcoats, for protective and decorative purposes. These coatings can be used on buildings, machineries,

equipments, vehicles as automotive original equipment manufacture (OEM) and refinish coatings, or in other coating applications. The coating can provide one or more protective layers for the underlying substrate and can also have an aesthetically pleasing value. Commercially-available polyurethane products can be used in coatings. Majority of the polyurethanes products are prepared from petroleum based feedstocks that are not available from renewable sources.

[03] Efforts have been made to use renewable sources for producing coatings or one or more components of a coating. For example, linear polymers or co-polymers containing bio-derived polyols having renewable contents can be used in coatings.

[04] There are continued needs for coating compositions and especially for those having components derived from renewable sources.

STATEMENT OF INVENTION

[05] This invention is directed to a coating composition comprising a branched copolyether polyol polymer derived from a monomer mixture via condensation reaction, said monomer mixture comprising 1 ,3-propanediol and at least one triol comonomer selected from 1 ,1 ,1 -trishydroxymethyl ethane,

1,1 ,1 -trishydroxymethyl propane, or a combination thereof.

[06] This invention is also directed to a process for coating a substrate, said process comprising the steps of:

a) providing the coating composition of this disclosure; b) applying said coating composition over said substrate to form a wet coating layer; and

c) curing said wet coating layer to form a dry coating layer over said substrate.

DETAILED DESCRIPTION

[07] The features and advantages of the present invention will be more readily understood, by those of ordinary skill in the art, from reading the following detailed description. It is to be appreciated that certain features of the invention, which are, for clarity, described above and below in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features of the invention that are, for brevity, described in the context of a single embodiment, may also be provided separately or in any sub-combination. In addition, references in the singular may also include the plural (for example, "a" and "an" may refer to one, or one or more) unless the context specifically states otherwise.

[08] The use of numerical values in the various ranges specified in this application, unless expressly indicated otherwise, are stated as

approximations as though the minimum and maximum values within the stated ranges were both proceeded by the word "about." In this manner, slight variations above and below the stated ranges can be used to achieve substantially the same results as values within the ranges. Also, the disclosure of these ranges is intended as a continuous range including every value between the minimum and maximum values.

[09] As used herein:

[10] The term "diol" or "diols" is meant a compound containing two reactive OH groups, also known as hydroxyl functionalities. The compound can have 3 to 10 carbons and have saturated or unsaturated carbon-carbon bonds.

[11] The term "triol" or "triols" is meant a compound containing three reactive OH groups. The compound can have 3 to 10 carbons and have saturated or unsaturated carbon-carbon bonds.

[12] The term "polyol" or "polyols" is meant a polymer molecule having an average hydroxyl functionality greater than 2. For example, a triol is a polyol having 3 hydroxyl functionalities. [13] The term "branched" is meant a polymer molecule that is composed of a polymer backbonre with one or more substituent side chains or branches. In one example, a branched polymer can have carbon-carbon backbone and carbon-carbon side chains or branches.

[14] The term "(meth)acrylate" means methacrylate or acrylate.

[15] The term "two-pack coating composition", also known as 2K coating composition, refers to a coating composition having two packages that are stored in separate containers and sealed to increase the shelf life of the coating composition during storage. The two packages are mixed just prior to use to form a pot mix, which has a limited pot life, typically ranging from a few minutes (15 minutes to 45 minutes) to a few hours (4 hours to 8 hours). The pot mix is then applied as a layer of a desired thickness on a substrate surface, such as an automobile body. After application, the layer dries and cures at ambient or at elevated temperatures to form a coating on the substrate surface having desired coating properties, such as, high gloss, mar- resistance and resistance to environmental etching.

[16] The term "crosslinkable component" refers to a component having "crosslinkable functional groups" that are functional groups positioned in each molecule of the compounds, oligomer, polymer, the backbone of the polymer, pendant from the backbone of the polymer, terminally positioned on the backbone of the polymer, or a combination thereof, wherein these functional groups are capable of crosslinking with crosslinking functional groups (during the curing step) to produce a coating in the form of crosslinked structures. One of ordinary skill in the art would recognize that certain crosslinkable functional group combinations would be excluded, since, if present, these combinations would crosslink among themselves (self-crosslink), thereby destroying their ability to crosslink with the crosslinking functional groups. A workable combination of crosslinkable functional groups refers to the combinations of crosslinkable functional groups that can be used in coating applications excluding those combinations that would self-crosslink.

[17] Typical crosslinkable functional groups can include hydroxyl, thiol, isocyanate, thioisocyanate, acid or polyacid, acetoacetoxy, carboxyl, primary amine, secondary amine, epoxy, anhydride, ketimine, aldimine, or a workable combination thereof. Some other functional groups such as orthoester, orthocarbonate, or cyclic amide that can generate hydroxyl or amine groups once the ring structure is opened can also be suitable as crosslinkable functional groups.

[18] The term "crosslinking component" refers to a component having "crosslinking functional groups" that are functional groups positioned in each molecule of the compounds, oligomer, polymer, the backbone of the polymer, pendant from the backbone of the polymer, terminally positioned on the backbone of the polymer, or a combination thereof, wherein these functional groups are capable of crosslinking with the crosslinkable functional groups (during the curing step) to produce a coating in the form of crosslinked structures. One of ordinary skill in the art would recognize that certain crosslinking functional group combinations would be excluded, since, if present, these combinations would crosslink among themselves (self- crosslink), thereby destroying their ability to crosslink with the crosslinkable functional groups. A workable combination of crosslinking functional groups refers to the combinations of crosslinking functional groups that can be used in coating applications excluding those combinations that would self-crosslink. One of ordinary skill in the art would recognize that certain combinations of crosslinking functional group and crosslinkable functional groups would be excluded, since they would fail to crosslink and produce the film forming crosslinked structures. The crosslinking component can comprise one or more crosslinking agents that have the crosslinking functional groups.

[19] Typical crosslinking functional groups can include hydroxyl, thiol, isocyanate, thioisocyanate, acid or polyacid, acetoacetoxy, carboxyl, primary amine, secondary amine, epoxy, anhydride, ketimine, aldimine, orthoester, orthocarbonate, cyclic amide or a workable combination thereof.

[20] It would be clear to one of ordinary skill in the art that certain crosslinking functional groups crosslink with certain crosslinkable functional groups. Examples of paired combinations of crosslinkable and crosslinking functional groups can include: (1) ketimine functional groups generally crosslink with acetoacetoxy, epoxy, or anhydride functional groups; (2) isocyanate, thioisocyanate and melamine functional groups generally crosslink with hydroxyl, thiol, primary and secondary amine, ketimine, or aldimine functional groups; (3) epoxy functional groups generally crosslink with carboxyl, primary and secondary amine, ketimine, or anhydride functional groups; (4) amine functional groups generally crosslink with acetoacetoxy functional groups; (5) polyacid functional groups generally crosslink with epoxy or isocyanate functional groups; (6) anhydride functional groups generally crosslink with epoxy and ketimine functional groups; and (7) hydroxyl functional groups also crosslink with acetoacetoxy functional groups.

[21] This disclosure is directed to a coating composition comprising a branched copolyether polyol polymer, also known as a poly(trimethylene ether) polyol. The branched copolyether polyol polymer can be derived from a monomer mixture via condensation reaction, wherein the monomer mixture can comprise 1,3-propanediol and at least one triol comonomer selected from 1,1,1 -trishydroxymethyl ethane, 1,1,1-trishydroxymethyl propane, or a combination thereof.

[22] The monomer mixture can comprise in a range of from 80 mole percent to 99.9 mole percent 1,3-propanediol (also referred to as PDO herein) and in a range of from 0.1 mole percent to 20 mole percent the triol comonomer.

[23] The branched copolyether polyol polymer can comprise repeating units of Formula I, Formula II, and optionally Formula III:

wherein R is methyl or ethyl and Q is one or more of Formula (Ilia)

[25] wherein m is 1-20 and n is 0 to 3.

[26] The branched copolyether polyol polymer can comprise end groups of one or more of Formula IV, V, VI, or a combination thereof:

[27] The branched copolyether polyol polymer can be polymerized in a batch, semi-continuous, or continuous polymerization process. The triol comonomers can be added prior to or during initial polymerization of 1,3- propanediol. [Examples of suitable processes can include those disclosed in U.S. Patent Nos. 6720459 and 6977291 , with further reaction of desired comonomers with the 1,3-propanediol reactant. In one example, the triol comonomer is 1,1,1 -trishydroxymethyl ethane and in another example the triol comonomer is 1,1,1 -trishydroxymethyl propane. In yet another example the triol monomers comprise a combination of 1,1,1 -trishydroxymethyl ethane and 1,1,1 -trishydroxymethyl propane.

[28] The branched copolyether polyol polymer can comprise in a range of from 80 to 99.9 mole percent 1,3-propanediol and in a range of from 0.1 to 20 mole percent the triol comonomer(s) in one example, in a range of from 90 to 99 mole percent 1,3-propanediol and in a range of from 1 to 10 mole percent triol comonomer(s) in another example, and in a range of from 2 to 6 mole percent triol comonomer(s) in yet another example. When the triol

comonomer is present at about 3.15 mole percent or higher, the branched copolyether polyol polymer can be an amorphous liquid polymer with no melt temperature. When the triol comonomer is present below 3.15 mole percent, the branched copolyether polyol polymer can be a crystalline or

semicrystalline polymer having a melt temperature in a range of from 0°C to 15°C. When the triol comonomers are polymerized with 1,3-propanediol, the resulting polyol quality can be superior to polyols obtained from other triols such glycerol. They tend to have no odor, low alkaline numbers, low color, low unsaturation, are less hydrophobic and contain thermally stable CH ₂ OH groups.

[29] The branched copolyether polyol polymer can comprise primary hydroxyl groups that are present both as pendant CH ₂ OH groups that are attached to the backbone of the polymer, end CH ₂ OH groups that are attached to an end of the polymer, or a combination thereof. The primary hydroxyl groups can be located randomly on the backbone and branched side chains of the polymer and as well as at the polymer ends. The branched copolyether polyol polymer can be essentially free from secondary hydroxyl groups. The term "essentially free from secondary hydroxyl groups" means less than 5% of the secondary hydroxyl groups. The branched copolyether polyol polymer can have less than 5% of the secondary hydroxyl groups in one example, less than 1 % of the secondary hydroxyl groups in another example, or less than 0.1% of the secondary hydroxyl groups in yet another example. The absence of secondary hydroxyl end groups and steric hindered hydroxyl groups on the backbone or side chain can make the copolyols with high reactivity towards polyisocyanates.

[30] The equivalent hydroxyl functionality of the copolyether polyol polymer can be defined as the average number of hydroxyl groups per molecule. The hydroxyl functionality and functionality distribution are useful parameters to characterize the polyols. Typically,a copolyol is a mixture of molecules with different numbers of hydroxyl groups, and the exact composition depends upon the type and amount of comonomer and manufacturing

polycondensation process. Physical properties can therefore depend on the composition and they can be controlled by varying the composition.

[31] One method for determination of hydroxyl functionality can be based on the assessment of the number average molecular weight (Mn) of the polyether polyol by gel permeation chromatography together with hydroxyl number determination from titration. The hydroxy functionality (f) can be calculated by using the equation:

f=M _n x OH#/56100 wherein Mn is the number average molecular weight and OH# is the total hydroxyl number determined by titration (mg), 56100 is a constant related to KOH.

[32] Alternatively, the equivalent hydroxyl functionality, fe, of the mixture can be calculated using the following equation:

[33] The branched copolyether polyol polymer can comprise at least two repeating units with different equivalent hydroxyl functionality. The

copolyether polyol can have an equivalent hydroxyl functionality in a range of from 2 to 5 and a Mn in a range of from 200 to 6000. In another example, The copolyether polyol can have a Mn in a range of from 200 to 4000.

[34] Using the NMR method, the number average molecular weight and the functionality of the branched copolyether polyol polymer can be calculated. ¹ H NMR spectrum (CDCl ₃ and trifluoroacetic anhydride solvents) of the copolymer can have the following main chemical shifts: .δ= 0.94, 1.00, 1.008 (s, CH ₃ -C(CH ₂ O) ₃ ), 1.89, 1.93, 2.01 (t, -O-CH ₂ -CH ₂ -CH ₂ -O, backbone), 3.30 to 3.58 <t, CH ₂ -O-CH ₂ - backbone), 4.3 -4.4 (t, HO-CH ₂ -C(CH ₃ )), 4.46 (HO- CH ₂ )

[35] Proton NMR distinguishes the protons corresponding to the end groups (CH ₂ -OH), middle ether groups (CH ₂ -O-CH ₂ ), methyl groups of co-monomer with varying functionality (CH ₂ -C(CH ₂ -O) ₃ ). As the branched 1,1,1 - tris(hydroxymethyl)ethane with three reacted hydroxyls do not have end groups, methyl groups of 1 ,1,1 tris(hydroxymethyl)ethane were used for calculating molecular weight and functionality contribution from 1,1,1 - tris(hydroxymethyl)ethane. Methyl group carbons have three hydrogens and the carbon atoms of end groups and ether linkages have two hydrogens. Hence, the response area of methyl groups needs be multiplied with 2/3 to equalize.

[36] The number average molecular weight of the branched copolyether polyol polymer can be calculated using the following equation:

Mn = (DP * mole% PDO * 58)/100 + (DP * mole%TME * 102) 100 +18 - unsat ends/mole * 18

DP =

and the equivalent hydroxyl functionality, or functionality, can be calculated as shown below, using the following abbreviations:

DP Degree of polymerization

PDO 1,3-propanediol

TME 1 ,1, 1-Tris(hydroxymethyl)ethane

u Unsaturated ends per polymer molecule

e Area of total ether linkages

h Area of PDO end groups

m, d, t 2/3 of the areas of 1 ,1 , 1 -tris(hydroxyrnethyl)ethane methyl groups with mono-, di- and tri- ether linkages, respectively.

[37] Polydispersity Index (Mw/Mn, also known as "polydispersity" or

"molecular weight distribution (MWD)") of the polymers can be measured by gel permeation chromatography (GPC). The GPC instrument can be calibrated using linear polytrimethylene ether glycol homopolymer. ASTM method D445-83 and ASTM method D792-91 can be used to determine the absolute (dynamic) viscosity and density of the polymer, respectively. Melting, crystallization and glass transition temperatures of the polymers can be obtained from differential scanning calorimetry (DSC). Surface tension can be measured for the polyols by ring (DuNouy) method using Cahn dynamic contact angle analyzer (model DCA-312). [38] The surface tension is a measure of the inward force acting on the surface of a liquid due to the attraction of molecules in the liquid. In general, high levels of intermolecular forces among the molecules in a liquid have high values of surface tension. The surface tension of the branched copolyether polyol polymer can be in a range of from 40 to 42.

[39] The monomer mixture can comprise bio-derived 1,3-propanediol, also known as "biologically-derived 1,3-propanediol". The 1,3-propanediol can be obtained by any of the various known chemical routes or by biochemical transformation routes from a renewable source.

[40] A bio-route via fermentation of a renewable resource can be used to obtain the bio-derived 1,3-propanediol. One example of renewable resources is corn since it is readily available and has a high rate of conversion to 1,3- propanediol and can be genetically modified to improve yields to the 1,3- propanediol. Examples of typical bio-route can include those described in US Patent No. 5, 686,276, US Patent No. 5,633,362 and US Patent No.

5,821,092.

[41] The bio-derived 1,3-propanediol, such as produced by the processes disclosed and referenced above, contains carbon from the atmospheric carbon dioxide incorporated by plants, which compose the feedstock for the production of the 1,3-propanediol. In this way, the bio-derived 1,3-propanediol contains only renewable carbon, and not fossil fuel-based or petroleum-based carbon. The 1,3-propanediol obtained from the renewable source and the coating compositions therefrom can be distinguished from their petrochemical derived counterparts on the basis of radiocarbon dating such as fraction of modern carbon (f _M ), also know as ¹⁴ C (f _M ) and dual carbon-isotopic

fingerprinting ¹³ C/ ¹² C such as the one known as δ ¹³ C. The fraction of modem carbon f _M is defined by National Institute of Standards and Technology (NIST) Standard Reference Materials (RFMs) 4990B and 4990C. The renewable sourced carbon content of the branched copolyol can be in a range of from 70% to 99.9%, for example in a range of from 80% to 99.9%, or in a range of from 90% to 99.9%, all percentage based on the weight of the total carbon content of the polymer. The bio based carbon content can be calculated based on number of carbons or determined according to ASTM-D6866. [42] The 1,3-propanediol used as the reactant or as a component of the reactant can have a purity of greater than about 99%, and more preferably greater than about 99.9%, by weight as determined by gas chromatographic analysis. (Examples for purifying 1,3-propanediols can be include those as disclosed in U.S. Patent No.: 7,084,311 , or U.S. Patent No.: 7,098,368.

[43] The branched copolyether copolyols disclosed herein can have a polydispersity within the range of 1.5 to 2.8, an alkalinity in the range of -5 to +5, more typically -3 to +2. The branched copolyether copolyols can have residual unreacted monomers and those unreacted monomers can be part of the polydispersity.

[44] The branched copolyols have typically an APHA color of less than 200, more typically less than 150, and most typically less than 100.

[45] The coating composition can further comprise a crosslinking agent having one or more crosslinking functional groups selected from isocyanate, melamine, amine, or a combination thereof. The crosslinking agent can be selected from aliphatic polyisocyanates, cycloaliphatic polyisocyanates, aromatic polyisocyanates, trifunctional isocyanates, isocyanate adducts, or a combination thereof. The crosslinking agent can be further selected from isophorone diisocyanate, toluene diisocyanate, hexamethylene diisocyanate, diphenylmethane diisocyanate, triphenyl triisocyanate, benzene triisocyanate, toluene triisocyanate, trimer of hexamethylene diisocyanate, or a combination thereof.

[46] The coating composition can further comprise one or more film forming polymers selected from acrylic polymers, polyester polymers, polyurethane polymers, other film forming polymers, or a combination thereof. The polymers can have functional groups. Any acrylic polymers or polyester polymers that are suitable for coatings can be suitable. The acrylic polymers, the polyester polymers, or both the acrylic polymers and the polyester polymers can have functional groups. In one example, the functional groups can be crosslinkable functional groups, such as hydroxyl groups.

[47] The coating composition can further comprise one or more pigments, one or more solvents, ultraviolet light stabilizers, ultraviolet light absorbers, antioxidants, hindered amine light stabilizers, leveling agents, rheology control agents, thickeners, antifoaming agents, wetting agents, catalysts, or a combination thereof.

[48] The coating composition of this disclosure can comprise conventional coating additives. Examples of such additives can include wetting agents, leveling and flow control agents, for example, Resiflow®S (polybutylacrylate), BYK® 320 and 325 (high molecular weight polyacrylates), BYK® 347

(polyether-modified siloxane) under respective registered tradmarks, leveling agents based on (meth)acrylic homopolymers; rheological control agents, such as highly disperse silica, fumed silica or polymeric urea compounds; thickeners, such as partially crosslinked polycarboxylic acid or polyurethanes; antifoaming agents; catalysts for the crosslinking reaction of the OH-functional binders, for example, organic metal salts, such as, dibutyltin dilaurate, zinc naphthenate and compounds containing tertiary amino groups, such as, triethylamine, for the crosslinking reaction with polyisocyanates. The additives are used in conventional amounts familiar to those skilled in the art.

[49] The coating compositions according to the disclosure can further contain reactive low molecular weight compounds as reactive diluents that are capable of reacting with the crosslinking agent. For example, low molecular weight polyhydroxyl compounds, such as, ethylene glycol, propylene glycol, trimethylolpropane and 1 ,6-dihydroxyhexane can be used.

[50] Depending upon the type of crosslinking agent, the coating

composition of this disclosure can be formulated as one-pack (1K) or two- pack (2K) coating composition. If polyisocyanates with free isocyanate groups are used as the crosslinking agent, the coating composition can be formulated as a two-pack coating composition in that the crosslinking agent is mixed with other components of the coating composition only shortly before coating application. If blocked polyisocyanates are, for example, used as the crosslinking agent, the coating compositions can be formulated as a one-pack (1K) coating composition. The coating composition can be further adjusted to spray viscosity with organic solvents or water before being applied as determined by those skilled in the art.

[51] In a typical two-pack coating composition comprising two packages, the two packages are mixed together shortly before application. The first package typically can contain the polymer having reactive groups, such as, an acrylic polymer having reactive hydroxyl groups, additives, and pigments. The first package can also have one or more solvents. The pigments can be dispersed in the first package using conventional dispersing techniques, for example, ball milling, sand milling, and attritor grinding. The second package can contain the crosslinking agent, such as, a polyisocyanate crosslinking agent, and solvents.

[52] The coating composition can be a solvent borne or a waterborne coating composition and can comprise one or more organic solvents or one or more reactive diluents. Any typical organic solvents can be used to form the coating composition of this disclosure. When the coating composition is a solvent borne coating composition, it can be essentially free from water or have in a range of from 0 to 20% of water. The term "essentially from water" is meant to have less than 5% of water. When the coating composition is a waterborne coating composition, it can comprise water, such as in a range of from 20% to 80% of water. All percentage is based on the total weight of the coating composition.

[53] The coating composition according to the disclosure can be suitable for vehicle and industrial coating and can be applied using known processes. In the context of vehicle coating, the coating composition can be used both for vehicle original equipment manufacturing (OEM) coating and for repairing or refinishing coatings of vehicles and vehicle parts. Curing of the coating composition can be accomplished at ambient temperatures, such as temperatures in a range of from 18°C to 35°C, or at elevated temperatures, such as at temperatures in a range of from 35°C to 150°C. Typical curing temperatures of 20°C to 80°C, in particular of 20°C to 60°C, can be used for vehicle repair or refinish coatings.

[54] The substrate suitable for this invention can be a plastic, bare metal such as blasted steel, aluminum or other metal or alloys. One example of the blasted steel can be the one available from East Coast Steel Inc, Columbia, SC 29290, USA. The substrate can also be plastic or metal substrates with one or more existing coating layers. One example can be a steel substrate coated with an electrocoat (e-coat) layer. Another example can be a steel substrate coated with an electrocoat (e-coat) layer and a primer layer. Yet another example can be a steel substrate coated with a primer layer. Yet another example can be a steel substrate coated with a primer layer and a colored coating layer. The primer layer can be produced with an epoxy primer, an acrylic primer, a polyester primer, or other primers known to those skilled in the art. An epoxy primer means a primer composition comprises at least one epoxy resin or its derivatives. An acrylic primer means a primer composition comprises at least one acrylic resin or its derivatives. A polyester primer means a primer composition comprises polyesters or polyester derivatives.

[55] The coating composition of this disclosure can be used as a primer, a basecoat, a top coat, or a clearcoat. It can also be used as a single layer coat that can function as a primer, a basecoat and a top coat.

[56] The coating composition can be a latex coating composition.

[57] This disclosure is also directed to a process for coating a substrate.

The process can comprise the steps of:

[58] a) providing the coating composition disclosed herein;

[59] b) applying said coating composition over said substrate to form a wet coating layer; and

[60] c) curing said wet coating layer to form a dry coating layer over said substrate.

[61] The wet coating layer can be cured at a temperature in a range of from 15°C to 180°C.

[62] Any of the coating compositions disclosed herein can be suitable for the process.

[63] The coating composition can be applied by conventional techniques, such as, spraying, electrostatic spraying, dipping, brushing, and flow coating. Typically, the dry coating layer can have a dry film thickness in a range of from 10 to 300 microns in one example, 20 to 300 microns in another example, 50 to 300 microns in yet another example, 50 to 200 microns in yet another example, and 50 to 130 microns in yet another example.

[64] The substrate can be a vehicle, one or more vehicle parts, or a combination thereof.

[65] In the following examples, all parts and percentages are on a weight basis unless otherwise indicated. "Mw" weight average molecular weight and "Mn" means number average molecular weight. TESTING PROCEDURES

[66] Dry Film Thickness - test method ASTM D4138.

[67] Molecular weight and hydroxyl number of the polytrimethylene ether diol are determined according to ASTM E222.

[68] Dry to touch time - Dry to touch time is determined by ASTM D1640.

[69] Orange Peel - Measured by Wavescan DOI (from Byk-Gardner 9104 Guilford Road, Columbia, MD 21046). A lower number indicates a better appearance.

[70] Polydispersity (Mw/Mn) of the polymers can be measured by gel permeation chromatography (GPC) unless specified otherwise. The GPC instrument can be calibrated using linear polytrimethylene ether glycol homopolymer.

[71] Absolute (dynamic) viscosity and density of the polymer can be measured using ASTM method D445-83 and ASTM method D792-91 , respectively.

[72] Melting, crystallization and glass transition temperatures of the polymers can be obtained from differential scanning calorimetry (DSC) (Model

Jade DSC from PerkinElmer, Inc., Shelton, CT, USA).

[73] Surface tension can be measured for the polyols by ring (DuNouy) method using Cahn dynamic contact angle analyzer (model DCA-312 from

Thermo Electron Corporation, Newington, NH, USA).

EXAMPLES

The present invention is further defined in the following Examples. It should be understood that these Examples, while indicating preferred embodiments of the invention, are given by way of illustration only. From the above discussion and these Examples, one skilled in the art can ascertain the essential characteristics of this invention, and without departing from the spirit and scope thereof, can make various changes and modifications of the invention to adapt it to various uses and conditions.

EXAMPLE 1

450 g (5.9 moles) of 1 ,3 propanediol (Susterra® propanediol from

DuPont Tate & Lyle Bioproducts, Loudon, TN), 78.9 g (0.66 moles; 10 mol%) of 1,1,1 -tris(hydroxymethyl) ethane (Aldrich) and 5.34 g of H ₂ SO ₄ (VWR, 95 wt %) were charged into a 1 L four-neck round bottomed flask fitted with mechanical stirrer and condenser to cool and collect byproducts. The reactor was flushed with dry nitrogen gas to remove air. The reaction mixture was heated to 165 °C and reaction was continued for 5.5 h. The reaction was stopped and the reaction products were allowed to cool.

Purification:

The obtained product was mixed with 500 mL of water and hydrolyzed at 90°C for 2 h. The temperature was then reduced to 60°C. 500 mL of 2 wt % Na ₂ CO ₃ solution was slowly added and mixed for 30 min. The product was transferred into a separating funnel. After separation, the lower part was collected and mixed with 1 L of water and again transferred into a separation funnel. The lower organic part was collected and dried at 90°C using rotary evaporator. The obtained product was characterized using NMR, GPC, DSC and wet chemical analysis including titration and viscosity measurement.

EXAMPLE 2

Synthesis:

2700 g (35.48 moles) of 1,3- propanediol, 270 g (2.25 moles; 6 mol%) of 1,1,1 -tris(hydroxymethyl) ethane (Aldrich) and 30.1 g of H ₂ SO ₄ (VWR, 95 wt %) were charged into 5 L four-neck round bottomed flask fitted with mechanical stirrer and condenser to cool and collect byproducts. The reactor was flushed with dry nitrogen gas to remove air. The reaction mixture was heated to 166 °C and reaction was continued for 14 h. The heating was then stopped and the reaction product was allowed to cool.

The obtained product was neutralized with 68 g sodium carbonate solution (68 g in 120 mL of deionized water) at 120°C for 6 h. The product was filtered using solka-floc filter aid. The product was characterized as disclosed in [Example 1.

EXAMPLE 3

Synthesis:

2733 g (35.9 moles) of 1,3-propanediol, 120 g (1 mole; 2.7 mol%) of 1,1,1 -tris(hydroxymethyl) ethane (Aldrich), 25.87 g of H ₂ SO ₄ (VWR, 95 wt %) and 2.54 g of sodium carbonate dissolved in 10.5 mL water were charged into 5 L four-neck round bottomed flask fitted with mechanical stirrer and condenser to cool and collect byproducts. The reactor was flushed with dry nitrogen gas to remove air. The reaction mixture was heated to 166 °C and reaction was continued for 21 h 15 min. The heating was then stopped and the reaction product was allowed to cool.

The obtained product was mixed with 1.5 L of water and hydrolyzed at

95 °C for 4 h. Then 330 mL of 10 wt % Na ₂ CO ₃ solution was slowly added and mixed for 30 min. The product was distilled under reduced pressure to remove water and filtered using solka-floc filter aid. The product was characterized using H NMR.

EXAMPLE 4

Synthesis:

2433 g (32 moles) of 1,3-propanediol, 120 g (1 mole; 3 mol%) of 1,1,1 - tris(hydroxymethyl) ethane (Aldrich), 25.37 g of H ₂ SO ₄ (VWR, 95 wt %) and 2.54 g of sodium carbonate dissolved in 10.5 mL water were charged into 5 L four-neck round bottomed flask fitted with mechanical stirrer and condenser to cool and collect byproducts. The reactor was flushed with dry nitrogen gas to remove air. The reaction mixture was heated to 166 °C and reaction was continued for 21 h 45 min. The heating was then stopped and the reaction product was allowed to cool.

The obtained product was mixed with 1.5 L of water and hydrolyzed at

95 °C for 4 h. Then 330 mL of 10 wt % Na ₂ CO ₃ solution was slowly added and mixed for 30 min. The product was distilled under reduced pressure to remove water and filtered using solka-floc filter aid. The product was characterized using ¹ H NMR.

EXAMPLE 5

The procedure was similar to the procedure disclosed in Example 4 except the sulfuric acid amount was 25.9 g and the reaction time was 22 hours.

Table 1 below summarizes the composition and properties of the branched polytrimethylene ether copolyol polymers prepared in Examples 1-5 using proton NMR method.

Table 1. Property of the Polyol Polymers.

As shown in Table 1 , it is possible to synthesize wide range of copolyols having different hydroxyl numbers, functionality and molecular weight by selecting the right amount of the triol and process conditions. The branched copolyol of example 1 is particularly suitable for polyurethane rigid foam applications because this copolyol comprised of short chains with high hydroxyl numbers whereas the rest of the copolyols are more suitable for flexible foam applications.

Table 2 below compares the properties of the branched

polytrimethylene ether copolyols with linear homopolymers. The Comparative Examples were commercial Cerenol® polymers obtained from E. I. du Pont de Nemours and Company, Wilmington, DE, USA.

The data in Table 2 demonstrates about 5 mol% of triol incorporation changed the crystalline polymer to amorphous polymer, and at 2.5 mol% of triol incorporation, the degree of crystallization and the rate of crystallization of the copolyol decreased, as evident from lower melt enthalpy and the increase in cold crystallization temperature . The molecular weight distribution is slightly broader and viscosity is higher for higher molecular weight branched polyois than that of linear polyol. The surface tension of branched copolyols are very similar to that of linear polyois suggesting the branched polyols have similar hydrophilic character of linear polyois in spite of higher hydroxyl functionality.

EXAMPLE 6

The branched copolyoi of Example 4 was mixed separately with castor oil polyol having MW of 980 daltons and a surface tension of 36.0 dynes/cm ( from spectrum), and soybean oil polyol having a hydroxyl functionality of 3.6 (from BioBased Technologies®, LLC, Fayetteville, AR) by 50/50 by weight. The resulting blends were homogeneous (completely miscible) indicating excellent compatibility of copolyoi with the vegetable based polyois. The surface tension of the castor oil blend was increased to 37.4 dynes/cm, which also confirmed excellent interaction between castor oil polyols and branched copolyol molecules.

EXAMPLE 7

Coating compositions were prepared according to Tables 3. The coating mixtures were applied over cold roll steel available from ACT Test Panel Technologies, Hillsdale, Michigan, USA, by drawdown with a blade. Average dry film thickness of the coatings was about 2 mils (about 50 microns). The coating was cured at ambient temperature in a range of from 20°C to 45°C for the time specified.

Dry time of the coating layers was measured according to ASTM

D1640. Dry film thickness was measured according to test method ASTM D4138. Orange peel was measured using Wavescan DOI, available from Byk- Gardner, Columbia, MD, USA.

1. The branched copolyether polyol polymer was from Example 3.

2. The comparative triol polymer was Arcol® Polyol LHT-112

Polypropylene-oxide available from Bayer MaterialScience LLC, Pittsburgh, PA, USA, under respective registered trademark. The linear polyol polymer was commercial Cerenol® H-1400 available from E. I. du Pont de Nemours and Company, Wilmington, DE, USA, under respective registered trademark.

4. OH EW: hydroxyl equivalent weight [g/mol of hydroxyl].

5. The crosslinking agent was DuPont Imron® FG572™ Activator, available from E. I. du Pont de Nemours and Company, Wilmington, DE, USA, under respective trademark or registered trademark.

The binder was commercial WJ-02® available from E. i. du Pont de

Nemours and Company, Wilmington, DE, USA, under respective registered trademark. WJ-02® contains 42 wt.% water.

7. From Dow Chemical Company, Midland, Ml 48640, USA.

8. The accelerator was commercial VG-805™ available from E. I. du Pont de Nemours and Company, Wilmington, DE, USA, under respective registered trademark.

EXAMPLE 8

Coating compositions were prepared according to Tables 4. The coatings were applied and cured as described above. The coatings were essentially free from water.

. e ranc e copo yet er po yo po ymer was rom xamp e .

2. The comparative triol polymer was Arcol® Polyol LHT-112 Polypropylene-oxide available from Bayer MaterialScience LLC, Pittsburgh, PA, USA, under respective registered trademark.

3. The linear polyol polymer was commercial Cerenol® H-1400 available from E. I. du Pont de Nemours and Company, Wilmington, DE, USA, under respective registered trademark.

4. OH EW: hydroxyl equivalent weight [g/mol of hydroxyl].

5. The crosslinking agent was DuPont Imron® 9T00-A™ Activator, available from E. I. du Pont de Nemours and Company, Wilmington, DE, USA, under respective trademark or registered trademark.

6. This catalyst was DABCO 33-LV® available from Air Products and

Chemicals, Inc., Allentown, PA, USA, under respective registered trademark.

7. This accelerator was VG-805™ available from E. I. du Pont de

Nemours and Company, Wilmington, DE, USA, under respective trademark.