Field of the invention

The present invention relates to a method for producing a terminal-functional polymer by reversible addition-fragmentation chain transfer (RAFT) polymerization, a polymer obtained by this method and the use of said polymer for sealant or adhesive application.

Background of the invention

For sealant or adhesive market, “hybrid systems” are getting more and more attention recently. Such systems combine the properties of functional groups and soft polymer backbone to afford a number of advantages, e.g. high backbone flexibility and high elongation, excellent elongation recovery, good adhesion to various substates, low shrinkage, non-staining and paintable, and low VOC.

Functional polymers made by conventional free radical polymerization are known to suffer from poor mechanical property, as the functional groups are randomly distributed along the polymer backbone, leading to an ill-defined polymer network with many short polymer segments be tween neighboring crosslinking points. Polymers with functional group only on polymer terminals or close to terminals are known to enhance mechanical property of the materials after curing. The advent of controlled radical polymerization technology has allowed the synthesis of poly mers where the functional groups are only placed on polymer terminals or close to polymer ter minals. Reversible addition-fragmentation chain transfer (RAFT) polymerization is a well- established technology for making polymers with such tailored architecture.

US 2004220364A1 discloses a process of making telechelic silyl-terminated polyacrylates by using RAFT polymerization, with the following steps: (a) RAFT polymerization of acrylates, (b) converting RAFT end group into thiol group by aminolysis, and (c) end group functionalization by reacting terminal thiol group with isocyanate silane. The process disclosed in US 2004220364A1 involves one more purification step between step (b) and step (c). Also isocyanate silane is quite expensive raw material.

There is a need for a simple and economic method towards the terminal functionalized poly mers with high end-group functionality, which are readily curable into solid materials for sealant or adhesive applications.

Summary of the invention

The objective of the invention is to provide a simple and cost-effective synthetic method towards precisely defined terminal-functional polymers by using RAFT polymerization. The polymers possess high end-group functionality. Another objective of the invention is to provide a terminal-functional polymer which shows the moisture curability and advantageous mechanical properties, compared with random copolymer. Such properties are useful for sealant or adhesive applications.

In one aspect, the present invention relates to a method for producing a terminal-functional polymer by reversible addition-fragmentation chain transfer (RAFT) polymerization in the presence of at least one thiocarbonylthio group-containing compound, comprising the steps of (a) polymerizing a radically polymerizable vinyl monomer, and (b) removing RAFT end group by aminolysis and coupling the polymer with a compound carrying functional groups in one-pot.

In another aspect, the present invention relates to a terminal-functional polymer obtained by the method according to the present invention.

In another aspect, the present invention relates to a sealant or adhesive composition, comprising the polymer according to the present invention.

In another aspect, the present invention relates to the use of the polymer according to the present invention for sealant or adhesive application.

In the method according to the present invention, the terminal functionalization can be done in one-pot with no purification step needed in-between, and high end group functionality can be achieved that leads to improved curability and low surface tackiness. The method according to the present invention is simple and emploies cheap commercial raw materials. The terminal- functional polymer obtained by the method according to the present invention provides significantly improved elongation properties for sealant or adhesive applications.

Detailed description of the invention

One aspect of the present invention relates to a method for producing a terminal-functional polymer by reversible addition-fragmentation chain transfer (RAFT) polymerization in the presence of at least one thiocarbonylthio group-containing compound, comprising the steps of (a) polymerizing a radically polymerizable vinyl monomer, and (b) removing RAFT end group by aminolysis and coupling the polymer with a compound carrying functional groups in one-pot.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

Expressions "a", "an", "the", when used to define a term, include both the plural and singular forms of the term.

All percentages, parts and ratios are by weight, unless otherwise specified. All such weights as they pertain to listed components are based on the specific ingredient level and, therefore, do not include carriers or by-products that may be included in commercially available materials, unless otherwise specified.

Step (a)

In the present invention, a radically polymerizable vinyl monomer is preferably polymerized to a conversion higher than 95%, more preferably higher than 97% in the presence of at least one thiocarbonylthio group-containing compound in step (a).

Vinyl Monomer

The vinyl monomer used in the present invention is not particularly limited as long as it is radically polymerizable. Examples of vinyl monomers which may be used include methacrylate esters, such as methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, tert-butyl methacrylate, 2-ethylhexyl methacrylate, tridecyl methacrylate, stearyl methacrylate, cyclohexyl methacrylate, benzyl methacrylate, 2-hydroxyethyl methacrylate, 2- hydroxypropyl methacrylate, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate, glycidyl methacrylate, tetrahydrofurfuryl methacrylate, ethylene glycol di methacrylate, triethylene glycol dimethacrylate, tetraethylene glycol dimethacrylate, 1,3-butylene glycol dimethacrylate, trimethylolpropane trimethacrylate, isopropyl methacrylate, pentyl methacrylate, hexyl methacrylate, heptyl methacrylate, octyl methacrylate, nonyl methacrylate, decyl methacrylate, dodecyl methacrylate, phenyl methacrylate, tolyl methacrylate, isobornyl methacrylate, 2-methoxyethyl methacrylate, 3-methoxybutyl methacrylate, 2-aminoethyl methacrylate, trifluoromethyl methacrylate, pentafluoroethyl methacrylate, and 2,2,2- trifluoroethyl methacrylate; acrylate esters, such as methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, hexyl acrylate, 2-ethylhexyl acrylate, cyclohexyl acrylate, octyl acrylate, decyl acrylate, dodecyl acrylate, phenyl acrylate, tolyl acrylate, benzyl acrylate, isobornyl acrylate, 2-methoxyethyl acrylate, 3-methoxybutyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, stearyl acrylate, glycidyl acrylate, trifluoromethyl acrylate, pentafluoroethyl acrylate, 2,2,2-trifluoroethyl acrylate, 3-dimethylaminoethyl acrylate, isobutyl acrylate, 4-hydroxybutyl acrylate, tert-butyl acrylate, acrylate of alkyl-modified dipentaerythritol, Carbitol acrylate, acrylate of [epsilon]-caprolactone-modified dipentaerythritol, caprolactone- modified tetrahydrofurfuryl acrylate, diacrylate of caprolactone-modified neopentyl glycol hydroxypivalate, ditrimethylolpropane tetraacrylate, dipentaerythritol hexaacrylate, dipentaerythritol pentaacrylate, tetraethylene glycol acrylate, tetrahydrofurfuryl acrylate, tripropylene glycol acrylate, trimethylolpropane ethoxy triacrylate, trimethylolpropane triacrylate, neopentyl glycol diacrylate, diacrylate of neopentyl glycol hydroxypivalate, 1,9-nonandiol acrylate, 1,4-butanediol acrylate, 1,6-hexanediol acrylate, pentaerythritol triacrylate, 2- acryloyloxypropylhydrogen phthalate, methyl 3-methoxyacrylate, and allyl acrylate; aromatic alkenyl compounds, such as styrene, a-methylstyrene, p-methylstyrene, p-methoxystyrene, divinylbenzene, and vinylnaphthalene; vinyl cyanide compounds, such as acrylonitrile and methacrylonitrile; conjugated diene compounds, such as butadiene and isoprene; halogen- containing unsaturated compounds, such as vinyl chloride, vinylidene chloride, tetrafluoroethylene, hexafluoropropylene, vinylidene fluoride, vinyl bromide, and chloroprene; vinyl ester compounds, such as vinyl acetate, vinyl propionate, vinyl pivalate, vinyl benzoate, vinyl cinnamate, divinyl carbonate, vinylethyl carbonate, and vinylphenyl carbonate; allyl ester compounds, such as allyl acetate, allyl propionate, allyl pivalate, allyl benzoate, allyl cinnamate, diallyl carbonate, allylmethyl carbonate, and allylphenyl carbonate; unsaturated group- containing ether compounds, such as vinyl phenyl ether, vinyl ethyl ether, divinyl ether, trimethylolpropane monovinyl ether, trimethylolpropane divinyl ether, trimethylolpropane trivinyl ether, pentaerythritol monovinyl ether, pentaerythritol divinyl ether, pentaerythritol trivinyl ether, pentaerythritol tetravinyl ether, 1,4-butanediol monovinyl ether, 1,4-butanediol divinyl ether, ethylene glycol monovinyl ether, ethylene glycol divinyl ether, propylene glycol monovinyl ether, propylene glycol divinyl ether, polyethylene glycol monovinyl ether, polyethylene glycol divinyl ether, polypropylene glycol monovinyl ether, polypropylene glycol divinyl ether, vinyl glycidyl ether, allyl phenyl ether, allyl ethyl ether, diallyl ether, vinyl allyl ether, trimethylolpropane monoallyl ether, trimethylolpropane diallyl ether, trimethylolpropane triallyl ether, pentaerythritol monoallyl ether, pentaerythritol diallyl ether, pentaerythritol triallyl ether, pentaerythritol tetraallyl ether, 1,4-butanediol monoallyl ether, 1,4-butanediol diallyl ether, ethylene glycol monoallyl ether, ethylene glycol diallyl ether, propylene glycol monoallyl ether, propylene glycol diallyl ether, polyethylene glycol monoallyl ether, polyethylene glycol diallyl ether, polypropylene glycol monoallyl ether, polypropylene glycol diallyl ether, and allyl glycidyl ether; maleimide compounds, such as maleimide, methylmaleimide, ethylmaleimide, propylmaleimide, butylmaleimide, hexylmaleimide, octylmaleimide, dodecylmaleimide, stearylmaleimide, phenylmaleimide, and cyclohexylmaleimide; acrolein and methacrolein; cyclopolymerizable compounds, such as 1,6-heptadiene and diallylammonium salts; and N-vinyl pyrrolidone, N- vinyl carbazole, etc. These compounds may be used alone or in combination. When a copolymer is produced from a plurality of vinyl monomers, any form may be acceptable, such as a random copolymer, a block copolymer, a graft copolymer, or a combination of any of these.

Among the vinyl monomers described above, preferred are styrene, a-methylstyrene, vinyl chloride, vinylidene chloride, methacrylate esters, acrylate esters, methacrylonitrile, acrylonitrile, vinyl acetate, and maleimide compounds, more preferred are methacrylate esters and acrylate esters, and most preferred are methyl methacrylate, n-butyl acrylate, or a combination of these.

Thiocarbonylthio Group-containing Compound

The thiocarbonylthio group-containing compound used in the present invention is at least one compound selected from the group consisting of a compound represented by general formula (I): wherein

R is selected from the group consisting of alkyl, substituted alkyl, aralkyl, substituted aralkyl, a polyvalent aliphatic hydrocarbon group, a polyvalent aromatic hydrocarbon group, a polyvalent araliphatic hydrocarbon group, a polyvalent alipharomatic hydrocarbon group, a polyvalent aliphatic hydrocarbon group containing a heteroatom, and a polyvalent aromatic hydrocarbon group containing a heteroatom; preferably from the group consisting of phenyl, benzyl, 1- phenylethyl, 2-(2-phenyl)propyl, 1-acetoxyethyl, 1-(4-methoxyphenyl)ethyl, ethoxycarbonylmethyl, 2-(2-ethoxycarbonyl)propyl, 2-(2-cyano)propyl, tert-butyl, 1, 1,3,3- tetramethylbutyl, 2-[2-(p-chlorophenyl)]propyl, vinylbenzyl, tert-butylsulfide, 2-carboxylethyl, carboxylmethyl, cyanomethyl, 1-cyanoethyl and 2-(2-cyano)butyl; and more preferably from the group consisting of phenyl, benzyl and 1-phenylethyl;

Z is selected from the group consisting of alkyl, substituted alkyl, alkoxy, aryloxy, aryl, substituted aryl, aralkyl, substituted aralkyl, N-aryl-N-alkylamino, N,N-diarylamino, N,N- dialkylamino, thioalkyl, and dialkylphosphinyl; and preferably from the group consisting of C2- Ci ₆ -alkyl, -S-C2-Ci6-alkyl, -0-C ₂ -Ci ₆ -alkyl, phenyl, benzyl, 4-chlorophenyl, 1-naphthyl, 2-naphthyl, diethoxyphosphinyl, thiomethyl (methylsulfide), phenoxy, thiophenyl, N,N-dimethylamino, N,N- diethylamino, N-phenyl-N-methylamino, N-phenyl-N-ethylamino, thiobenzyl and pentafluorophenoxy; more preferably from the group consisting of C2-Ci6-alkyl, -S-C2-Ci6-alkyl, and phenyl; and most preferably from the group consisting of Ce-Cn-alkyl, -S-Cs-C _M -alkyl, and phenyl; and p is an integer from 1 to 10, preferably from 2 to 8, more preferably from 2 to 4; and most preferably 2.

The thiocarbonylthio group-containing compounds used in the present invention may be used alone or in combination.

When the vinyl monomer used in the present invention is polymerized, the thiocarbonylthio group-containing compound must be present in the reaction system during polymerization. The addition method for the thiocarbonylthio group-containing compound is not particularly limited. In order to control the molecular weight and the molecular weight distribution of the polymer and in order to increase the introduction rate of functional groups, preferably, the thiocarbonylthio group-containing compound is dissolved or dispersed in the reaction system before polymerization is initiated. For example, in the case of solution polymerization, the thiocarbonylthio group-containing compound is preferably dissolved in a solvent or a vinyl monomer before addition.

The amount of the thiocarbonylthio group-containing compound used is not particularly limited. Since the degree of polymerization of the resultant polymer depends on the number of moles of the thiocarbonylthio group-containing compound added, the amount of the thiocarbonylthio group-containing compound may be calculated based on the required degree of polymerization or number-average molecular weight of the polymer.

Polymerization Initiator

In the present invention, when vinyl monomers are radically polymerized in the presence of a thiocarbonylthio group-containing compound, the polymerization initiator or polymerization initiation method used is not particularly limited, and any polymerization initiator or polymerization initiation method commonly used in the art may be employed. Examples of polymerization initiators include, but are not limited to, peroxide polymerization initiators, such as methyl ethyl ketone peroxide, methyl isobutyl ketone peroxide, cyclohexanone peroxide, methyl cyclohexanone peroxide, isobutyryl peroxide, 3,5,5-trimethylhexanoyl peroxide, lauroyl peroxide, benzoyl peroxide, tert-butyl hydroperoxide, cumene hydroperoxide, diisopropylbenzene hydroperoxide, p-menthane hydroperoxide, 1,1,3,3-tetramethylbutyl hydroperoxide, di-tert-butyl peroxide, tert-butyl-a-cumyl peroxide, di-a-cumyl peroxide, 1,4- bis[(tert-butylperoxy)isopropyl]benzene, 1 ,3-bis[(tert-butylperoxy)isopropyl]benzene, 2,5- dimethyl-2,5-bis(tert-butylperoxy)hexane, 2,5-dimethyl-2,5-bis(tert-butylperoxy)-3-hexyne, 1,1- bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane, n-butyl-4,4-bis(tert-butylperoxy)valerate, 2,2- bis(tert-butylperoxy)butane, tert-butylperoxy acetate, tert-butylperoxy isobutylate, tert- butylperoxy octoate, tert-butylperoxy pivalate, tert-butylperoxy neodecanoate, tert-butylperoxy- 3, 5, 5-trimethyl hexanoate, tert-butylperoxy benzoate, tert-butylperoxy laurate, 2,5-dimethyl-2,5- bis(benzoylperoxy)hexane, bis(2-ethylhexyl)peroxy dicarbonate, diisopropylperoxy dicarbonate, di-sec-butylperoxy dicarbonate, di-n-propylperoxy dicarbonate, bis(3-methoxybutyl)peroxy dicarbonate, bis(2-ethoxyethyl)peroxy dicarbonate, bis(4-tert-butylcyclohexyl)peroxy dicarbonate, O-tert-butyl-O-isopropylperoxy carbonate, and succinic acid peroxide; azo polymerization initiators, such as 2,2'-azobis-(2-amidinopropane)dihydrochloride, 2,2'- azobis(dimethylisobutyrate), 2,2'-azobis-(4-methoxy-2,4-dimethylvaleronitrile), 2,2'- azobis(isobutyronitrile) (AIBN), 1,T-azobis(cyclohexane-1-carbonitrile), azocumene, 2,2'- azobis(2-methylbutyronitrile), 2,2'-azobis-(2,4-dimethylvaleronitrile, 4,4'-azobis(4-cyanovaleric acid), 2-(tert-butylazo)-2-cyanopropane, 2,2'-azobis(2,4,4-trimethylpentane), and 2,2'-azobis(2- methylpropane); inorganic peroxides, such as potassium persulfate and sodium persulfate; vinyl monomers which thermally generate radical species, such as styrene; compounds which generate radical species by light, such as benzoin derivatives, benzophenone, acylphosphine oxide, and photo-redox systems; and redox polymerization initiators including sodium sulfite, sodium thiosulfate, sodium formaldehyde sulfoxylate, ascorbic acid, ferrous sulfate, or the like, as a reducing agent, and potassium peroxydisulfate, hydrogen peroxide, tert-butyl hydroperoxide, or the like, as an oxidizing agent. These polymerization initiators may be used alone or in combination. It may also be possible to use a polymerization initiation system by electron irradiation, X-ray irradiation, radiation irradiation, or the like. With respect to polymerization initiation methods, the methods described in Moad and Solomon "The Chemistry of Free Radical Polymerization", Pergamon, London, 1995, pp. 53-95 may be employed.

In the present invention, the amount of polymerization initiator used is not particularly limited. In order to produce a polymer with a narrow molecular weight distribution, the amount of radical species generated during polymerization is preferably 1 mole or less, and more preferably 0.5 moles or less, relative to 1 mole of thiocarbonylthio group in the thiocarbonylthio group- containing compound. In order to control the amount of radical species generated during polymerization, in addition to the control of the amount of the polymerization initiator, preferably, temperature is controlled in the case of the polymerization initiator which causes thermal dissociation, or the amount of energy is controlled in the case of the polymerization initiation system which generates radicals by light or electron beams. Because of ease of control of polymerization, using a polymerization initiator which causes thermal dissociation, the polymerization reaction is carried out preferably at temperatures which allow the polymerization initiator to have a half-life of 0.5 to 50 hours, more preferably at temperatures which allow the polymerization initiator to have a half-life of 1 to 20 hours, and most preferably at temperatures which allow the polymerization initiator to have a half-life of 5 to 15 hours.

Polymerization Media

The polymerization can be carried out in the presence of polymerization media.

The polymerization media can be solvents. Examples of solvents which may be used include, but are not limited to, hydrocarbon solvents, such as heptane, hexane, octane, and mineral spirit; ester solvents, such as ethyl acetate, n-butyl acetate, isobutyl acetate, ethylene glycol monomethyl ether acetate, and diethylene glycol monobutyl ether acetate; ketone solvents, such as acetone, methyl ethyl ketone, methyl isobutyl ketone, diisobutyl ketone, and cyclohexanone; alcohol solvents, such as methanol, ethanol, isopropanol, n-butanol, sec- butanol, and isobutanol; ether solvents, such as tetrahydrofuran, diethyl ether, dibutyl ether, dioxane, ethylene glycol dimethyl ether, and ethylene glycol diethyl ether; and aromatic petroleum solvents, such as toluene, xylene, benzene, Swasol 310 (manufactured by Cosmo Oil Co., Ltd.), Swasol 1000 (manufactured by Cosmo Oil Co., Ltd.), and Swasol 1500 (manufactured by Cosmo Oil Co., Ltd.). These solvents may be used alone or in combination. The types and amounts of solvent used may be determined in consideration of the solubility of the monomers, the solubility of the resultant polymer, the polymerization initiator concentration and the monomer concentration suitable for achieving a satisfactory reaction rate, the solubility of the thiocarbonylthio group-containing compound, effects on human body and environment, availability, cost, etc., and are not particularly limited.

The polymerization media can be plasticizers. The plasticizer as used in accordance with the invention may comprise one or more selected from the group consisting of: phthalates, trimelli- tates, aliphatic dibasic esters, polyesters, polymeric, epoxides, phosphates.

In a preferred embodiment said plasticizer is selected from the group consisting of : butyl benzyl phthalate, butyl 2-ethylhexyl phthalate, diisohexyl phthalate, diiso-heptyl phthalate, di(2- ethylhexyl) phthalate, diisooctyl phthalate, di-n-octyl phthalate, disononyl phthalate, diisodecyl phthalate, diiso undecyl phthalate, diisotredecyl phthalate, diiso (Cn, C12, C13) phthalate, diinbutyl) phthalate, di(n-C7, Cg) phthalate, di(n-C ₆ , Cs, C10) phthalate, diiso(n-nonyl) phthalate, di(n- C7, Cg, C11) phthalate, di(n-Cg, Cn) phthalate, di(n-undecyl) phthalate, tri(n-Cs, C10) trimellitate, tri(2-ethylhexyl) trimellitate, tri(isooctyl) trimellitate, tri(isononyl) trimellitate, di(n-C7, Cg) adipate, di(2-ethylhexyl) adipate, di(isooctyl) adipate, di(isononyl) adipate, polyesters of adipinic acid or glutaric acid and propylene glycol or butylene glycol or 2, 2-dimethyl-1, 3-propanediol, epoxidized oils such as epoxidized soy bean oil, epoxidized linseed oil, epoxidized tall oil, octyl epoxy tal- late, 2-ethylhexyl epoxy tallate, Isodecyl di-phenyl phosphate, tri(2-ethylhexyl) phosphate, tricresyl phosphate, di(2-ethylhexyl) terephthalate, di(isononyl) cyclohexane- 1,2-dicarboxcylate and combinations thereof. In a particularly preferred embodiment said plasticizer is selected from the group consisting of: diisohexyl phthalate, diisoheptyl phthalate, di(2-ethylhexyl) phthalate, diisooctyl phthalate, di-n-octyl phthalate, disononyl phthalate, diisodecyl phthalate, diiso undecyl phthalate, diisotredecyl phthalate, diiso (Cn, C12, C13) phthalate, di(n-butyl) phthalate, di(n-C7, Cg) phthalate, di(n-C ₆ , Cs, C10) phthalate, diiso(n-nonyl) phthalate, di(n-C7, Cg, C11) phthalate, di(n-Cg, Cn) phthalate, di(n-undecyl) phthalate, tri(n-Cs, C10) trimellitate, tri(2- ethylhexyl) trimellitate, tri(isooctyl) trimellitate, tri(isononyl) trimellitate, di(n-C7, Cg) adipate, di(2- ethylhexyl) adipate, di(isooctyl) adipate, di(isononyl) adipate, polyesters of adipinic acid or glutaric acid and propylene glycol or butylene glycol or 2, 2-dimethyl-1, 3-propanediol, epoxidized oils such as epoxidized soy bean oil, di(isononyl) cyclohexane- 1, 2-dicarboxcylate and combinations thereof, preferably di(isononyl) adipate (e.g. Plastomoll DNA) and di(isononyl) cyclohex- ane-1, 2-dicarboxcylate (e.g. Hexamoll DINCH).

The polymerization can be carried out in batch, semi-batch, and continuous processes, preferably in semi-batch processes. In some preferred embodiments, polymerization temperature is about 60 to 90 °C, preferably about 65 to 80 °C. In some preferred embodiments, the total polymerization time is 3 to 15 h, preferably 4 to 10 h.

In the present invention, the degree of polymerization for a radically polymerizable vinyl monomer is not particularly limited and is set depending on the number-average molecular weight (M _n ).

Step (b)

In the present invention, removing RAFT end group by aminolysis and coupling the polymer with a compound carrying functional groups are carried out in one-pot in step (b).

In the aminolysis, the thiocarbonylthio group-containing vinyl polymer is allowed to react with amine compounds to obtain a thiol group-containing vinyl polymer.

The amine compounds include amines and their analogues. Examples of such amine compounds include, but are not limited to, hydroxylamine sulfate, hydroxylamine, N-(2- aminoethyl)ethanolamine, N-methylethanolamine, 3-amino-1-propanol, allylamine, diallylamine, isopropylamine, diisopropylamine, 3,3'-iminobis(propylamine), ethylamine, diethylamine, triethylamine, 2-ethylhexylamine, 3-(2-ethylhexyloxy)propylamine, 3-ethoxypropylamine, diisobutylamine, 3-(diethylamino)propylamine, di-2-ethylhexylamine, 3-

(dibutylamino)propylamine, tert-butylamine, sec-butylamine, isobutylamine, n-butylamine, n- propylamine, isopropylamine, 3-(methylamino)propylamine, 3-(dimethylamino)propylamine, N- methyl-3,3'-iminobis(propylamine), 3-methoxypropylamine, isopropanolamine, 3,3'- iminodipropionitrile, monoethanolamine, diethanolamine, N-ethylethylenediamine, ethyleneimine, ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, carbohydrazides, guanidine hydrochloride, guanidine nitrate, guanidine carbonate, guanidine phosphate, guanidine sulfamate, aminoguanidine hydrochloride, aminoguanidine bicarbonate, guanylthiourea, guanylurea phosphate, guanylurea sulfate, glycylglycine, 2-chloroethylamine, 1,4-diaminobutane, 1,2-diaminopropane, 1,3-diaminopropane, diaminomaleonitrile, cyclohexylamine, cyclopentylamine, dicyclohexylamine, dimethylamineborane, hydrazine, dimethylhydrazine, melamine, 3,9-bis(3-aminopropyl)- 2,4,8, 10-tetraoxaspiro[5,5]undecane, CTU guanamine, thiocarbohydrazide, thiosemicarbazide, thiourea, dihydrazide dodecanedioate, trans-1,2-cyclohexanediamine, dihydrazide adipate, dihydrazide sebacate, dihydrazide isophthalate, thiourea dioxide, 2- hydroxyethylaminopropylamine, 2-bromoethylamine, hexamethylenediamine, 1,6- hexamethylenebis(N,N-dimethylsemicarbazide), n-hexylamine, polyethyleneimine, formamidine, formamidine acetate, ammonia, monomethylamine, dimethylamine, trimethylamine, monomethylhydrazine, 3-(lauryloxy)propylamine, acetanilide, acetoacet-o-anisidide, acetoacetanilide, acetoacet-m-xylidide, acetoacet-o-chloroanilide, acetoacet-2,5,- dimethoxyanilide, acetoacet-2,5-dimethoxy-4-chloroanilide, acetoacet-o-toluidide, acetoacet-p- toluidide, o-anisidine, p-anisidine, aniline, p-aminoacetanilide, ethyl p-aminobenzoate ester, 2- amino-4-chlorophenol, 2-aminothiazole, 2-aminothiophenol, 2-amino-5-nitrobenzonitrile, o- aminophenol, m-aminophenol, p-aminophenol, p-aminobenzaldehyde, 4-aminobenzonitrile, 3- isopropoxyaniline, N-ethylaniline, 2,4-xylidine, 3,4-xylidine, m-xylylenediamine, p-cresidine, dianisidine, 1,4-diaminoanthraquinone, 4,4'-diamino-3,3'-diethyldiphenylmethane, 4,4'- diaminobenzanilide, N, N-diethylaniline, diaminodiphenyl ether, diaminonaphthalene, diaminoanthracene, diphenylamine, dibenzylamine, N,N-dimethylaniline, 3,3'-dimethyl-4,4'- diaminodiphenylmethane, 1,1,T,T-tetramethyl-4,4'-(methylenedi-p-phenylene)disemicarb azide, 2,4,5-trichloroaniline, o-tolidine, o-toluidine, m-toluidine, p-toluidine, m-toluylenediamine, sodium naphthionate, o-nitroaniline, m-nitroaniline, p-nitroaniline, o-nitro-p-chloroaniline, m-nitro-p- toluidine, phenylhydrazine, o-phenylenediamine, m-phenylenediamine, p-phenylenediamine, p- phenetidine, phenethylamine, benzylamine, benzophenone hydrazone, mesidine, N- methylaniline, 2-methyl-4-nitroaniline, 2-methyl-4-methoxydiphenylamine, leuco-1,4- dia inoanthraquinone, para ine, p-hydroxyphenylglycine, acetaldehyde ammonia, acetoguanamine, 3-amino-1, 2, 4-triazole, 2-aminopyridine, 3-aminopyridine, 4-aminopyridine, 1- (2-aminoethyl)piperazine, N-(3-aminopropyl)morpholine, and 1-amino-4-methylpiperazine.

Among them, when primary amines with a boiling point of 100 °C or less, such as methylamine and ethylamine, or secondary amines with a boiling point of 100 °C or less, such as dimethylamine and diethylamine, are used, excess amine compounds can be easily removed by distillation under reduced pressure, and thereby the purification step can be simplified, which is preferable.

When ammonia is used, as in primary or secondary amines with a boiling point of 100 °C or less, excess ammonia can be removed by distillation under reduced pressure, and thereby the purification step can be simplified, which is preferable.

In the present invention, the amount of amine compounds used is not particularly limited and preferably 0.5 to 100 moles, preferably 1 to 20 moles, and more preferably 1 to 10 moles, based on 1 mole of thiocarbonylthio group.

In the present invention, when the thiocarbonylthio group-containing vinyl polymer is treated with the amine compounds, the reaction conditions are not particularly limited. For example, a method in which the polymer is dissolved in an organic solvent, and the amine compound is added thereto; a method in which the amine compound is added to a water-based dispersion or emulsion; or a method in which the amine compound is directly added to the solid or molten polymer itself may be employed. The treatment temperature is not particularly limited. In view of reactivity and stability of the polymer, the treatment temperature is -50 °C to 300 °C, preferably - 10 °C to 200 °C, more preferably 10 °C to 100 °C, and most preferably 20 °C to 90 °C.

In the present invention, coupling the polymer with a compound carrying functional groups can be carried out via a thiol-ene reaction, thiol-Michael addition or thiol-epoxy reaction.

Compound carrying functional groups In one embodiment, the compound carrying functional groups is at least one compound having the formula (II): wherein R ¹ is H or methyl, and R ² represents or contains a crosslinkable functional group.

The crosslinkable functional group is not particularly restricted, but may include one or more of crosslinkable silyl, epoxy and acrylamide groups.

In one preferred embodiment, the thiol group-containing vinyl polymer is allowed to react with a compound carrying silyl groups represented by general formula (11-1) via the thiol-ene reaction:

(11-1) wherein R ³ is H or methyl, each X is independently of one another -OCH ₃ , -OCH2CH ₃ or - OCH2CH2CH3, and Y is H, -CH ₃ , -CH2CH3, -OCH3, -OCH2CH3 or -OCH ₂ CH ₂ CH ₃ .

Examples of compounds (11-1) include vinyltrimethoxysilane (VTMOS), vinylmethyldimethox- ysilane, vinyltriethoxysilane, vinylmethyldiethoxysilane, and a combination thereof.

For the thiol-ene reaction, the reaction conditions are not particularly limited and known in the art. For example, the thiol-ene reaction can be done in the presence of an initiator, under heat or light irradiation.

In one preferred embodiment, the thiol group-containing vinyl polymer is allowed to react with a compound carrying silyl groups represented by general formula (II-2) via the thiol-Michael addition: wherein R ⁴ is H or methyl, Z ¹ is Ci-C4-alkylene, preferably propylene, each X is independently of one another -OCH ₃ , -OCH ₂ CH ₃ or -OCH ₂ CH ₂ CH ₃ , and Y is H, -CH ₃ , -CH ₂ CH ₃ , -OCH ₃ , - OCH ₂ CH ₃ or -OCH ₂ CH ₂ CH ₃ .

Examples of compounds (II-2) include g-methacryloxypropyltrimethoxysilane (MEMO), y- methacryloxypropyltriethoxysilane, g-methacryloxypropyltripropoxysilane, g- methacryloxypropylmethyldimethoxysilane, g-methacryloxypropylmethyldiethoxysilane, g- methacryloxypropylmethyldipropoxysilane, methacryloxymethyldimethoxysilane, methacryloxymethyltrimethoxysilane, methacryloxymethyltriethoxysilane, (methacryloxymethyl)- methyldimethoxysilane, (methacryloxymethyl)-methyldiethoxysilane, g- acryloxypropyltrimethoxysilane (TSPA), g-acryloxypropyltriethoxysilane, g- methacryloxymethyldiethoxysilane, g-acryloxypropyltripropoxysilane, g- acryloxypropylmethyldimethoxysilane, g-acryloxypropylmethyldiethoxysilane, g- acryloxypropylmethyldipropoxysilane, and a combination thereof.

In one preferred embodiment, the thiol group-containing vinyl polymer is also allowed to react with a compound carrying epoxy groups or acrylamide groups of the formula (II) via the thiol- Michael addition.

The compound carrying epoxy groups of the formula (II) includes, for example, glycidyl methacrylate and glycidyl acrylate. In certain embodiments, a particularly preferred epoxy functional compound is commercially available under the designation S-100 from Synasia. That compound is 3,4-epoxycyclohexylmethyl methacrylate [CAS 82428-30-6], having a chemical formula CiiHie0 ₃ and a molecular weight of 196.2.

The compound carrying acrylamide groups of the formula (II) includes, for example, (meth)acrylamide and its derivatives including the N-substituted alkyl and aryl derivatives thereof. These include N-methyl (meth)acrylamide, N,N-dimethyl (meth)acrylamide, t-octyl (meth)acrylamide and the like.

For the thiol-Michael addition, the reaction conditions are not particularly limited and known in the art. In another embodiment, the compound carrying functional groups is at least one epoxy silane compound.

In another preferred embodiment, the thiol group-containing vinyl polymer is allowed to react with at least one epoxy silane compound via the thiol-epoxy reaction. For example, the thiol- epoxy reaction can be done in the presence of a base catalyst, which catalyzes nucleophilic attack of the thiol on epoxy groups.

The epoxy silane compound includes, for example, glycidyloxyalkyltrialkoxysilane, glycidyloxyalkylalkyldialkoxysilane, glycidyloxyalkylcycloalkyldialkoxysilane, glycidyloxyalkylaryldialkoxysilane, glycidyloxycycloalkyltrialkoxysilane, glycidyloxycycloalkylalkyldialkoxysilane, glycidyloxycycloalkylcycloalkyldialkoxysilane, glycidyloxycycloalkylphenyldialkoxysilane, glycidyloxyphenyltrialkoxysilane, glycidyloxyphenylalkyldialkoxysilane, glycidyloxyphenylcycloalkyldialkoxysilane, and glycidyloxyphenylphenyldialkoxysilane, preferably 3-glycidyloxypropylmethyldiethoxysilane, 3- glycidyloxypropyltrimethoxysilane, and 3-glycidyloxypropyltriethoxysilane, more preferably 3- glycidyloxypropyltrimethoxysilane.

For the thiol-epoxy reaction, the reaction conditions are not particularly limited and known in the art.

In the present invention, removing RAFT end group by aminolysis and coupling the polymer with a compound carrying functional groups can be carried out in one stage or consecutive stages without purification of intermediates.

Another aspect of the present invention relates to a terminal-functional polymer obtained by the method according to the present invention.

Molecular Weight / Degree of Polymerization / End group functionality

In the present invention, the molecular weight of the resultant polymer is not particularly limited and is set depending on the application. In view of balance between workability and heat resistance, strength, or the like, the number-average molecular weight (M _n ) determined by gel permeation chromatography (GPC) is in the range of 5,000 to 500,000, preferably in the range of 8,000 to 100,000, and more preferably in the range of 10,000 to 60,000. In the present invention, the molecular weight distribution of the resultant polymer is not particularly limited. Because of excellent workability and strength, the ratio (M _w /M _n ) of the weight-average molecular weight (M _w ) to the number-average molecular weight (M _n ) determined by gel permeation chromatography (GPC) is 3 or less, preferably 2 or less, and more preferably 1.5 or less. In the present invention, the end group functionality of the terminal-functional polymer is more than 80%, preferably more than 85%, more preferably more than 90%. Another aspect of the present invention relates to a sealant or adhesive composition, compris ing the polymer according to the present invention.

Catalysts

The sealant or adhesive composition according to the present invention may contain catalysts as necessary. Examples of the catalysts include, but are not limited to, titanate esters, such as tetrabutyl titanate and tetrapropyl titanate; organotin compounds, such as dibutyltin dilaurate, dibutyltin bisacetylacetonate, dibutyltin oxide, dibutyltin dimethoxide, dibutyltin maleate, dibu tyltin diacetate, tin octylate, and tin naphthenate; lead compounds, such as lead octylate; amine compounds, such as butylamine, octylamine, dibutylamine, monoethanolamine, diethanolamine, triethanolamine, diethylenetriamine, triethylenetetramine, oleylamine, cyclohexylamine, benzyl- amine, diethylaminopropylamine, xylylenediamine, triethylenediamine, guanidine, diphenylguan- idine, 2,4,6-tris(dimethylaminomethyl)phenol, morpholine, N-methylmorpholine, and 1,3- diazabicyclo[5.4.6]undecene-7; carboxylate salts of these amine compounds; alkaline catalyst, such as potassium hydroxide, sodium hydroxide, sodium and potassium methylate; acid or acid salt such as a lower alkyl carboxylic acid (e.g. C2 to C ₆ carboxylic acid), such as acetic acid, valeric acid; a poly-carboxylic acid such as citric acid, malic acid, maleic acid, succinic acid, malonic acid, hippuric acid, tartaric acid, oxalic acid; a medium/long chain acid such as lauric acid, stearic acid; phosphoric acids such as phenyl phosphoric acid; any other acid such as le- vulinic acid, benzoic acid, boric acid, trifluoroacetic acid; organic bismuth compound, such as bismuth carboxylate, especially bismuth octoate, bismuth ethylhexanoate, bismuth neodecano- ate or bismuth pivalate. These catalysts may be used alone or in combination.

In the sealant or adhesive composition according to the present invention, the amount of cata lyst used is not particularly limited. Preferably, the catalyst is used in an amount of 0 to 10% by weight relative to the polymer according to the present invention.

Additives

The sealant or adhesive composition according to the present invention may also include one or more additives, such as those described below.

For example, in various embodiments, the composition includes Ultraviolet (UV) light absorbers selected from the group consisting of hydroxyphenylbenzotriazole, tris-aryl-s-triazine, hy- droxybenzoate, 2-hydroxybenzophenone and cyanoacrylate ultraviolet light absorbers (UVAs).

In some embodiments, the UVA may include 5-chloro-2-(3-t-butyl-2-hydroxy-5-methylphenyl)- 2H-benzotriazole, 2-(3,5-bis-a-cumyl-2-hydroxyphenyl)-2H-benzotriazole, 4,6-diphenyl-2-(4- hexyloxy-2-hydroxyphenyl)-s-triazine, 4,6-bis-(2,4-dimethyhphenyl)-2-(2-hydroxy-4- octyloxyphenyl)-s-triazine, hexadecyl 3,5-di-tert-butyl-4-hydroxybenzoate or 4-octyloxy-2- hydroxybenzophenone.

Many of the UVAs are commercial, for example TINUVIN 326, TINUVIN 234, TINUVIN 1577, TINUVIN 1600, CYASORB UV 1164, CYASORB THT, CYASORB UV 2908, CHIMASSORB 81 , UVINUL 3030, ADK LA-F70, ADK LA-1000, TINUVIN 400, etc.

Further, fillers based on magnesium silicate hydrate such as, for example, talc, based on alumi num hydroxide such as, for example, AI(OH)3, based on a feldspar, based on quartz powder and/or based on a calcium silicate and/or aluminum silicate may be used and may have a parti cle size from 1 to 20 micrometers. Adding one or more fillers may serve to improve the mechan ical properties of the composition. In various embodiments, the fillers are chosen from calcium silicate, magnesium silicate hydrate, aluminum silicate, quartz powder and/or aluminum hydrox ide such as, for example, aluminum trihydrate. Fillers based on CaCCh, T1O2, carbon black and/or BaSCU as well as fillers with a significant Fe content and/or containing additional heavy metals may be used.

Lightweight fillers, in particular those based on polyurethane including their copolymers, poly amide wax and/or polyolefin wax may also be used. Lightweight fillers may also be used to re duce the density of the sealant or adhesive composition. Alternatively or additionally, hollow filing bodies may also be used.

Thixotropy agents, in particular based on feldspar, silicic acid/silica, fumed silica, sepiolite and/or bentonite may be used to adjust rheological properties, in particular for thixotropic behav ior, of the composition.

Plasticizers, in particular based on an adipate, a benzoate, a citrate, a phthalate, a hydrogenat ed phthalate, an ester of a polyethylene glycol, and/or a terphenyl, preferably the same plasticizer used as polymerization media as decribed hereinabove, may be used, for example, to increase the flexibility of the sealant or adhesive composition.

Adhesion promoters may be used to improve the adhesion of the sealant or adhesive composi tion to a substrate.

Examples of suitable adhesion promoters for improving adhesion include silane containing compounds, such as organosilanes, aminosilanes, epoxysilanes, amino alkoxy silanes, vinyl alkoxy silanes, isocyanato alkoxy silanes, isocyanurate functional alkoxy silanes, (meth)acrylic silanes, anhydridosilanes or adducts of the aforementioned silanes with primary aminosilanes, aminosilanes or urea silanes, polyamines such as polyethyleneimine, or combinations thereof. Specific examples of adhesion promoters can include vinyltriethoxysilane, vinyltrimethoxysilane, vinyl tris(2-methoxyethoxysilane), vinyl triisopropoxysilane, (meth)acryloyloxypropyl trimethoxy silane, (3-methacryloxypropyl)-trimethoxysilane, (3-methacryloxypropyl)-triethoxysilane, (3- methacryloxypropyl)-triisopropoxy silane, 2-methyl-2-propenoic acid 3-[tris-(1-methylethoxy)- silyl]-propyl ester, (3-methacryloxypropyl)-methyldiethoxysilane, 3-glycidoxypropyl methyldieth- oxy silane, 3-glycidoxypropylmethyldimethoxysilane, or a mixture thereof. In some examples, the organosilane comprises vinyltrimethoxysilane, vinyltriethoxysilane, vinyl tris(2- methoxyethoxysilane), vinyl triisopropoxysilane, gamma-methacryloxypropyltrimethoxy silane, or combinations thereof. For example, the organosilane can comprise vinyltriethoxysilane, gamma-glycidoxypropyltrimethoxysilane, gamma-aminopropyltrimethoxysilane, gamma- isocyanato propyl trimethoxysilane, n-beta-(aminoethyl) gamma-aminopropyl trimethoxy silane, n-(2-aminoethyl)-3-aminopropyl methyl dimethoxy silane, 3-aminopropyl methyl dimethoxy silane, bis-(gamma-trimethoxysilylpropyl amine), n-phenyl-gamma-aminopropyltrimethoxysilane, gamma-isocyanato propyl methyl dimethoxy silane, beta-(3,4-epoxycyclohexyl) ethyl triethoxy silane, gamma-glycidoxypropyltrimethoxysilane, (gamma-trimethoxysilylpropyl) isocyanurate, vinyltrimethoxysilane, vinyl triglycidoxyipropylmethylsilane, aminosilanes, or a combination thereof. In some embodiments, the adhesion promoter can include poly amines (i.e. , polymers formed from either an amine-group containing monomer or an imine monomer as polymerized units such as aminoalkyl vinyl ether or sulfides; acrylamide or acrylic esters, such as dimethyl- aminoethyl(meth)acrylate; N-(meth)acryloxyalkyl-oxazolidines such as poly(oxazolidinylethyl methacrylate), N-(meth)acryloxyalkyltetrahydro-l,3-oxazines, and monomers that readily gener ate amines by hydrolysis). Suitable polyamines can include, for example, poly(oxazolidinylethyl methacrylate), poly(vinylamine), or polyalkyleneimine (e.g., polyethyleneimine).

In some embodiments, the amount of the adhesion promoter present in the compositions can be 0% by weight or greater (e.g., 1% by weight or greater, 2% by weight or greater, 3% by weight or greater, 4% by weight or greater, 5% by weight or greater, 6% by weight or greater, 8% by weight or greater, 10% by weight or greater, 12% by weight or greater, or 15% by weight or greater), based on the total weight of the composition.

Anti-aging agents may also be used, such as sterically hindered phenols, phenyleneamine and/or hindered amine light stabilizers such as 4,6-bis(dodecylthiomethyl)-o-cresol, ethylene- bis(oxyethylene)bis(3-(5-tert-butyl-4-hydroxy-m-tolyl)propio nate), thiodiethylene-bis(3-(3,5-di- tert-butyl-4-hydroxyphenyl)propionate), pentaerythritol tetrakis(3-(3,5-di-tert-butyl-4- hydroxyphenyl)-propionate) and/or phenylene amines such as, for example, N-isopropyl-N'- phenyl-p-phenylenediamine. Anti-aging agents may be used to scavenge the free radicals formed due to aging processes involving the composition and may contribute to delaying and/or preventing aging such as yellowing or embrittlement of the sealant or adhesive composition.

Dehydrating agents, e.g. those based on an organofunctional alkoxysilane, based on a zeolite such as an alkali aluminum zeolite and/or based on a mono functional isocyanate may also be used. Flame retardants, in particular those based on phosphate esters, based on ammonium poly phosphate, based on melamine, based on aluminum hydroxide and/or based on magnesium hydroxide may also be used to improve the fire prevention behavior of the sealant or adhesive composition such as, for example, to delay the onset of burning of the sealant or adhesive, to spontaneously terminate the burning process and/or to reduce the formation of smoke.

Vulcanization promoters may also be used, such as diphenylguanidine, thiuram, and/or sulfur (e.g. sulfur paste).

Whitening agent or colorant may also be used, such as PO2, pigments and/or dyes.

In various embodiments, at least one organic solvent, in particular based on an ester and/or an ether such as, for example, ethyl acetate and/or monopropylene glycol monomethyl ether can be used.

Another aspect of the present invention relates to the use of the polymer according to the pre sent invention for sealant or adhesive application.

The invention will now be described in more detail with the following examples which are given for purely illustrative purposes and which are not intended to limit the scope of the invention in any manner.

Examples

Materials:

Butyl acrylate (BA) is from Sigma. RAFT agent is from Boron Molecular (BM1812). For Examples 9 and 10, plasticizer Hexamoll DINCH is from BASF, precipitated calcium carbonate (PCC) is from Guangxi Huana New Material Technology Co., Ltd (CCS-25, 80 nm), ground calcium carbonate (GCC) is Omycarb 5 (5 pm), and organotin catalyst (dibutyltin diacetylacetonate, DBTA) is from Nitto Kasei Co., Ltd (U-220H). All other reagents are from Sinopharm.

Target number-average molecular weight (M _n ):

Theoretical number-average molecular weight (M _n ) of a polymer synthesized can be estimated by the following equation: wherein [Monomer] and [RAFT] are concentrations (mol/L) of monomer and RAFT agent, respectively. C% is the monomer conversion. M(mon) and M(RAFT) are molecular weights of monomer and RAFT agent, respectively. Target number-average molecular weight (M _n ) is the theoretical M _n estimated by above equation when assuming monomer conversion (C%) is 100%.

GPC Measurement:

Molecular weight and polydispersity of polymers are determined by gel permeation chromatography (GPC) using PSS SDV 10e5/10e4/10e3 columns (300*8 nm) and THF as eluent. The polymers are dissolved in THF at 1.5 mg/ml_ for 12 h at room temperature, filtered by 0.45 pm membrane before injection. The molecular weight is calibrated by conventional GPC against polystyrene (PS) standards.

Example 1:

The telechelic polymer with a target number-average molecular weight (M _n ) of 10,000 g/mol was synthesized with semi-batch process in one-pot with a symmetric RAFT agent 1,4- phenylenebis(methylene) didodecyl dicarbonotrithioate.

The butylacrylate (BA) polymer backbone was synthesized in the first step. RAFT agent, butyl acrylate and ethyl acetate in amounts shown in Table 1 were added into a flask in initial charge. With N2 bubbling for 30 minutes, the resulting mixture was then heated to 78 °C to start polymerization under N2 atmosphere. Under stirring, Feed 1 was added for 150 minutes, Feed 2 for 180 minutes, and the polymerization was kept for 210 minutes. Residual monomer and solvent were removed by evaporation under vacuum. The resulting polymer was dissolved in acetonitrile again as solid content = 50%. Feed 3 and Feed 4 were simultaneously added into the flask. The reaction was heated to 50 °C and kept for 120 minutes. The pure telechelic polymer was obtained by evaporation.

Table 1: Semi-batch synthesis of Example 1

Initial charge 8 g of ethyl acetate, 13.188 g of RAFT agent, 40 g of butyl acrylate Feed 1 160 g of butyl acrylate Feed 2 16.43 g of AIBN solution (2% in ethyl acetate) Feed 3 29.28 g of butylamine, Feed 4 19.87 g of MEMO

According to GPC, the butylacrylate polymer backbone has a number-average molecular weight (M _n ) of 10,400 g/mol, PDI=1.23. According to ¹ H NMR, the monomer conversion of the polymerization is 97%. After evaporation, the residual monomer is <0.3%. End group functionality with MEMO is 91%.

Example 2:

The telechelic polymer with a target number-average molecular weight (M _n ) of 10,000 g/mol was synthesized with semi-batch process in one-pot with a symmetric RAFT agent 1,4- phenylenebis(methylene) didodecyl dicarbonotrithioate.

The butylacrylate (BA) polymer backbone was synthesized in the first step by RAFT polymerization same way as Example 1. RAFT agent, butyl acrylate and ethyl acetate in amounts shown in Table 2 were added into a flask in initial charge. Wth N ₂ bubbling for 30 minutes, the resulting mixture was then heated to 78 °C to start polymerization under N ₂ atmosphere. Under stirring, Feed 1 was added for 150 minutes, Feed 2 for 180 minutes, and the polymerization was kept for 210 minutes. Residual monomer and solvent were removed by evaporation under vacuum. The resulting polymer was dissolved in acetonitrile again as solid content = 50%. Feed 3 and Feed 4 were simultaneously added into the flask. The reaction was heated to 50 °C and kept for 120 minutes. The pure telechelic polymer was obtained by evaporation.

Table 2: Semi-batch synthesis of Example 2

Initial charge 8 g of ethyl acetate, 13.188 g of RAFT agent, 40 g of butyl acrylate Feed 1 160 g of butyl acrylate Feed 2 16.43 g of AIBN solution (2% in ethyl acetate) Feed 3 29.28 g of butylamine Feed 4 11.25 g of TSPA

According to GPC, the butylacrylate polymer backbone has a number-average molecular weight (M _n ) of 10,400 g/mol, PDI=1.23. According to ¹ H NMR, the monomer conversion of the polymerization is 97%. After evaporation, the residual monomer is <0.3%. End group functionality with TSPA is 94%.

Example 3:

The telechelic polymer with a target number-average molecular weight (M _n ) of 10,000 g/mol was synthesized with semi-batch process in one-pot with a symmetric RAFT agent 1,4- phenylenebis(methylene) didodecyl dicarbonotrithioate.

The butylacrylate (BA) polymer backbone was synthesized in the first step by RAFT polymerization same way as Example 1. RAFT agent, butyl acrylate and ethyl acetate in amounts shown in Table 3 were added into a flask in initial charge. With N2 bubbling for 30 minutes, the resulting mixture was then heated to 78 °C to start polymerization under N2 atmosphere. Under stirring, Feed 1 was added for 150 minutes, Feed 2 for 180 minutes, and the polymerization was kept for 210 minutes. Residual monomer and solvent were removed by evaporation under vacuum. Dissolve the polymer in acetonitrile again as solid content = 50%. The reaction was heated to 75 °C. Feed 3 was added into the flask and the reaction was kept for 60 minutes. Feed 4 was added into the flask and the reaction was kept for another 240 minutes. The pure telechelic polymer was obtained by evaporation.

Table 3: Semi-batch synthesis of Example 3

Initial charge 8 g of ethyl acetate, 13.188 g of RAFT agent, 40 g of butyl acrylate Feed 1 160 g of butyl acrylate Feed 2 16.43 g of AIBN solution (2% in ethyl acetate) Feed 3 29.28 g of butylamine Feed 4 118.61 g of VTMOS, 0.33 g of AIBN

According to GPC, the butylacrylate polymer backbone has a number-average molecular weight (M _n ) of 10,400 g/mol, PDI=1.23. According to ¹ H NMR, the monomer conversion of the polymerization is 97%. After evaporation, the residual monomer is <0.4%. End group functionality with VTMOS is 90%.

Example 4: The telechelic polymer with a target number-average molecular weight (M _n ) of 50,000 g/mol was synthesized with semi-batch process in one-pot with a symmetric RAFT agent 1,4- phenylenebis(methylene) didodecyl dicarbonotrithioate.

The butylacrylate (BA) polymer backbone was synthesized in the first step. RAFT agent, butyl acrylate and acetonitrile in amounts shown in Table 4 were added into a flask in initial charge. With N ₂ bubbling for 30 minutes, the resulting mixture was then heated to 76 °C to start polymerization under N ₂ atmosphere. Under stirring, Feed 1 was added for 150 minutes, Feed 2 for 180 minutes, and the polymerization was kept for 210 minutes. The reaction was heated to 82 °C, then Feed 3 was added for 60 minutes and the polymerization was kept for 120 minutes. Residual monomer was removed by evaporation under vacuum. The resulting polymer was dissolved in acetonitrile again as solid content = 50%. Feed 4 and Feed 5 were simultaneously added into the flask. The reaction was heated to 30 °C and kept for 300 minutes. The pure telechelic polymer was obtained by evaporation.

Table 4: Semi-batch synthesis of Example 4

Initial charge 15 g of acetonitrile, 3.297 g of RAFT agent, 50 g of butyl acrylate Feed 1 200 g of butyl acrylate Feed 2 10.27 g of AIBN solution (1% in acetonitrile) Feed 3 1.14 g of AIBN solution (1% in acetonitrile) Feed 4 7.32 g of butylamine Feed 5 2.81 g of TSPA According to GPC, the butylacrylate polymer backbone has a number-average molecular weight (M _n ) of 48,600 g/mol, PDI=1.31. According to ¹ H NMR, the monomer conversion of the polymerization is 97%. After evaporation, the residual monomer is <0.4%. End group functionality with MEMO is 90%.

Example 5:

The telechelic polymer with a target number-average molecular weight (M _n ) of 50,000 g/mol was synthesized with semi-batch process in one-pot with a symmetric RAFT agent 1,4- phenylenebis(methylene) didodecyl dicarbonotrithioate.

The butylacrylate (BA) polymer backbone was synthesized in the first step by RAFT polymerization same way as Example 4. RAFT agent, butyl acrylate and acetonitrile in amounts shown in Table 5 were added into a flask in initial charge. With N2 bubbling for 30 minutes, the resulting mixture was then heated to 76 °C to start polymerization under N2 atmosphere. Under stirring, Feed 1 was added for 150 minutes, Feed 2 for 180 minutes, and the polymerization was kept for 210 minutes. The reaction was heated to 82 °C, then Feed 3 was added for 60 minutes and the polymerization was kept for 120 minutes. Residual monomer was removed by evaporation. The resulting polymer was dissolved in acetonitrile again as solid content=60%. Feed 4 and Feed 5 were simultaneously added into the flask. The reaction was heated to 30 °C and kept for 120 minutes. Feed 6 was added into the flask and the reaction was kept for another 120 minutes. The pure telechelic polymer was obtained by evaporation.

Table 5: Semi-batch synthesis of Example 5

Initial charge 15 g of acetonitrile, 3.297 g of RAFT agent, 50 g of butyl acrylate Feed 1 200 g of butyl acrylate Feed 2 10.27 g of AIBN solution (1% in acetonitrile) Feed 3 1.14 g of AIBN solution (1% in acetonitrile) Feed 4 7.32 g of butylamine Feed 5 2.48 g of MEMO Feed 6 1.41 g of TSPA

According to GPC, the butylacrylate polymer backbone has a number-average molecular weight (M _n ) of 48,600 g/mol, PDI=1.31. According to ¹ H NMR, the monomer conversion of the polymer ization is 97%. After evaporation, the residual monomer is <0.4%. End group functionality with MEMO and TSPA are 92% totally.

Example 6:

The telechelic polymer with a target number-average molecular weight (M _n ) of 50,000 g/mol was synthesized with semi-batch process in one-pot with a symmetric RAFT agent 1,4- phenylenebis(methylene) didodecyl dicarbonotrithioate.

The butylacrylate (BA) polymer backbone was synthesized in the first step by RAFT polymeriza tion same way as Example 4. RAFT agent, butyl acrylate and acetonitrile in amounts shown in Table 6 were added into a flask in initial charge. With N ₂ bubbling for 30 minutes, the resulting mixture was then heated to 76 °C to start polymerization under N ₂ atmosphere. Under stirring, Feed 1 was added for 150 minutes, Feed 2 for 180 minutes, and the polymerization was kept for 210 minutes. The reaction was heated to 82 °C, then Feed 3 was added for 60 minutes and the polymerization was kept for 120 minutes. Residual monomer was removed by evaporation. The resulting polymer was dissolved in acetonitrile again as solid content=60%. Feed 4 and Feed 5 were simultaneously added into the flask. The reaction was heated to 30 °C and kept for 120 minutes. The pure telechelic polymer was obtained by evaporation.

Table 6: Semi-batch synthesis of Example 6

Initial charge 15 g of acetonitrile, 3.297 g of RAFT agent, 50 g of butyl acrylate Feed 1 200 g of butyl acrylate Feed 2 10.27 g of AIBN solution (1% in acetonitrile) Feed 3 1.14 g of AIBN solution (1% in acetonitrile) Feed 4 7.32 g of butylamine Feed 5 2.83 g of 3-glycidyloxypropyltrimethoxysilane

According to GPC, the butylacrylate polymer backbone has a number-average molecular weight (M _n ) of 48,500 g/mol, PDI=1.35. According to ¹ H NMR, the monomer conversion of the polymer ization is 97%. After evaporation, the residual monomer is <0.3%. End group functionality with 3-glycidyloxypropyltrimethoxysilane is 93%.

Example 7:

The telechelic polymer with a target number-average molecular weight (M _n ) of 30,000 g/mol was synthesized with semi-batch process in one-pot with a symmetric RAFT agent 1,4- phenylenebis(methylene) didodecyl dicarbonotrithioate.

The butylacrylate (BA) polymer backbone was synthesized in the first step. RAFT agent, butyl acrylate and acetonitrile in amounts shown in Table 7 were added into a flask in initial charge. With N2 bubbling for 30 minutes, the resulting mixture was then heated to 76 °C to start polymerization under N2 atmosphere. Under stirring, Feed 1 was added for 150 minutes, Feed 2 for 180 minutes, and the polymerization was kept for 210 minutes. Residual monomer was removed by evaporation. The resulting polymer was dissolved in acetonitrile again as solid content=50%. Feed 3 and Feed 4 were added in one-pot. The reaction was heated to 30 °C and kept for 240 minutes. The pure telechelic polymer was obtained by evaporation. Table 7: Semi-batch synthesis of Example 7

Initial charge 32 g of acetonitrile, 5.495 g of RAFT agent, 50 g of butyl acrylate

Feed 1 200 g of butyl acrylate

Feed 2 13.69 g of AIBN solution (1% in acetonitrile)

Feed 3 12.20 g of butylamine

Feed 4 4.68 g of TSPA

According to GPC, the butylacrylate polymer backbone has a number-average molecular weight (M _n ) of 29800 g/mol, PDI=1.26. According to ¹ H NMR, the monomer conversion of the polymeri zation is 99%. After evaporation, the residual monomer is <0.2%. End group functionality with TSPA is 95% totally.

Example 8 (Comparative example):

The crosslinkable random polymer with a target number-average molecular weight (Mn) of 50,000 g/mol was synthesized with semi-batch process in one-pot with a symmetric RAFT agent 1 ,4-phenylenebis(methylene) didodecyl dicarbonotrithioate. The random polymer was synthesized in one-pot. RAFT agent, butyl acrylate, ethyl acetate, MEMO and AIBN in amounts shown in Table 8 were added in initial charge. With N ₂ bubbling for 30 minutes, the resulting mixture was then heated to 75 °C to start polymerization under N ₂ atmosphere. Under stirring, Feed 1 was added for 60 minutes, and the polymerization was kept for 240 minutes. Residual monomer was removed by evaporation. The solid content of final polymer solution is 75%.

Table 8: Semi-batch synthesis of crosslinkable random polymer with Mn=50,000

Initial charge 36 g of ethyl acetate, 1.58 g of RAFT agent, 120 g of butyl acrylate, 4.77 g of MEMO, 0.67 g of AIBN solution (1% in ethyl acetate)

Feed 1 5.91 g of AIBN solution (1% in ethyl acetate)

According to 1H NMR, the monomer conversions of butyl acrylate and MEMO are 96.9% and 100%, respectively. The resulting polymer has a number-average molecular weight (M _n ) of 48,600 g/mol, PDI=1.42, determined by GPC.

Application Examples:

Example 9: moisture curability test Formulation: 26 parts by weight of polymer, 24 parts by weight of DINCH, 36 parts by weight of precipitated calcium carbonate (PCC), 12 parts by weight of ground calcium carbonate (GCC), 0.8 parts by weight of (3-aminopropyl)trimethoxysilane (AMMO), 0.8 parts by weight of VTMOS, 0.5 parts by weight of dibutyltin diacetate (DBTA)

A typical curing procedure is as follows:

1. Blending polymer and DINCH to ensure good flowability.

2. Mixing PCC, GCC, VTMOS and AMMO in sequence (water content: -900 ppm)

3. Putting mixture into speed mixer under vacuum atmosphere for 10 min (water content: -130 ppm).

4. Adding catalyst DBTA and mixing it under vacuum atmosphere for 1 min.

5. Sealing and packing.

Curing is done in a humidity control room (23 °C, 50% RH).

Table 9: moisture curability test result

All samples are readily curable within relatively short time (within 1 h). The cured sample has low surface tackiness (not tacky or slightly tacky).

Example 10: Tensile elongation properties by a manual stretching method

The moisture curing is performed with the same formulation and procedure as in Example 9.

Tensile elongation at break (E _b ) by a manual stretching method:

Taking a sample with initial length of U and slowly stretching the two ends with a speed of 20 mm/min until the sample is broken. The final length of the sample (L) before broken is recorded by a ruler. The tensile elongation at break (E _b ) is defined by the following equation:

E _b = (L-l_o)/l_o*100% Table 10. moisture curability and tensile elongation test results

The samples with the present invention are all readily curable with no or low surface tackiness, owing to the precisely-defined telechelic structure with high end group functionality. The sample in comparative example is also moisture-curable, but exhibits very low elongation at break, due to the random structure of its backbone.