WO2001094467A2

WO2001094467A2 - Soft polymer composition including epoxy

Info

Publication number: WO2001094467A2
Application number: PCT/US2001/017965
Authority: WO
Inventors: James Hall; Xiaorong Wang
Original assignee: Bridgestone Corporation
Priority date: 2000-06-05
Filing date: 2001-06-04
Publication date: 2001-12-13
Also published as: JP2003535947A; US6384134B1; WO2001094467A3; JP5329015B2; EP1290089A2

Abstract

A polymer gel composition includes a polymer having a maleimide and alkenyl units, a crosslinking agent, a maleated polyalkylene, an epoxy polymer, and, optionally, an extender. This composition has superior adhesion properties, high-temperature stability, mechanical strength, and modability.

Description

SOFT POLYMER COMPOSITION INCLUDING EPOXY

BACKGROUND OF THE INVENTION

The present invention relates to high damping polymers with superior adhesion properties, high-temperature stability, mechanical strength and moldability. The free radically-initiated polymerizations of isobutylene withmaleic anhydride, styrene with maleic anhydride, and alkyl vinyl ethers with maleic anhydride are known. Further, imidization between a maleic anhydride and a primary amine group is known. Two or more polymers may be blended together to form a wide variety of random or structured morphologies to obtain products that potentially offer desirable combinations of characteristics. However, it may be difficult or even impossible in practice to achieve many potential combinations through simple blending. Frequently, the polymers are thermodynamically immiscible, which precludes generating a truly homogeneous product. While immiscibility may not be a problem since it may be desirable to have a two-phase structure, the situation at the interface between these two phases very often does lead to problems. The typical case is one of high interfacial tension and poor adhesion between the two phases. This interfacial tension contributes, along with high viscosities, to the inherent difficulty of imparting the desired degree of dispersion to random mixtures and to their subsequent lack of stability, giving rise to gross separation or stratification during later processing or use. Poor adhesion can lead, in part, to the very weak and brittle mechanical behavior often observed in dispersed blends and may render some highly structured morphologies impossible.

SUMMARY OF THE INVENTION

The present invention provides a polymer gel composition that includes a polymer including anhydride and alkenyl units; a crosslinking agent; a maleated polyalkylene; an extender; and an epoxy. The polymer gel can be formed by reacting the polymeric constituents with a grafting agent followed by mixing with the epoxy polymer. A blend of a maleated polyalkylene and a poly(alkenyl-co-maleimide) and an epoxy polymer provides high damping, soft materials with good adhesion properties. The polymer composition exhibits improved properties such as tensile strength, maximum elongation, tear strength, damping properties, high temperature stability, good adhesion, and the like, with emphasis on good adhesion. More particularly, the combination of a grafted polymer with an epoxy polymer improves the tensile strength, tear strength, damping properties, high-temperature compression set, and adhesion of the grafted polymer.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

A representative polymer gel composition of the present invention contains 0.5-200 parts by weight of a poly(alkenyl-co-maleimide) having at least one maleated polyalkylene segment grafted thereto through the at least one functional linkage formed by a cross-linking reaction with a diamine grafted agent; and up to 1000 parts by weight of a hyperbranched epoxy polymer. The general term poly(alkenyl-co-maleirnide) includes species such as poly(alkenylbenzene-cø- maleimide), poly(R¹R²ethylene-co-maleimide), and poly(alkylvinyI ether-cø- maleimide).

The poly(alkenyl-co-maleirnide) is a centipede polymer formed by imidizing a poly(alkenyl-co-maleic anhydride) with a primary amine. The centipede polymer has a high molecular weight spine and many relatively short side chains formed from the addition of the primary amines. The main chain usually is longer than the entanglement length, which is herein defined theoretically as an order of magnitude of 100 repeating units, while the side chains are less than the entanglement length. Preferred alkenyl monomer units of the poly(alkenylbenzene-co-maleimide) include one or combination of styrene, α-methyl styrene, 1-vinylnaphthalene, 2- vinylnaphthalene, 1-α-methy 1-vinylnaphthalene, 2-α-methyl vinylnaphthalene, as well as alkyl, cycloalkyL aryl, alkaryl, and aralkyl derivatives thereof, in which the total number of carbon atoms in the combined hydrocarbon is generally not greater than 12, as well as any di- or tri- vinyl aromatic hydrocarbons. Preferred vinyl aromatic hydrocarbons include styrene and α-methylstyrene. The terms "alkenyl benzene" and "vinyl aromatic" are interchangeable as used herein. Preferred R^ethylene contributed monomer units of the poly(R¹R²ethylene-co-maleimide) include alkenes such as ethylene, propylene, butylene, isobutylene, pentene, hexene, heptene, and the like, as well as any di- or tri- alkene, with preference given to isobutylene. Preferred alkyl vinyl ether contributed monomer units of the poly(alkylvinyl ether-co-maleimide) include alkylvinyl ethers such as methylvinyl ether, ethylvinyl ether, propylvinyl ether, butylvinyl ether, and any other alkyl vinyl ether wherein the number of carbons in the alkyl substituent is not greater than about 12.

The poly(a-kenyl-co-maleimides) are graft-reacted through a difunctional linking or grafting agent to a maleated polyalkylene to yield a maleated polymer having at least one polyalkylene segment grafted thereto through at least one functional linkage thus formed. The alkylene moiety of the polyalkylene is ethylene and/or propylene.

A preferred polyalkylene is polypropylene. The maleated polypropylene may be any of the conventionally known polypropylene compounds that are subsequently maleated by methods known in the art. The polypropylene grafted segment(s) have weight molecular weights (M_w) of about 10,000 up to about 10,000,000 or higher, preferably about 20,000 to about 300,000.

The crystallinity, or tacticity, of the polypropylene may vary from being substantially amorphous to being completely crystalline, that is from about 10-100% crystallinity. Most typically, because of the extensive commercial use of isotactic polypropylene, the grafted polypropylene will be substantially crystalline, e.g., greater than about 90%. Generally, the polypropylene is substantially free of ethylene. However, under certain circumstances small amounts of ethylene, on the order of less than about 10% by weight, may be incorporated. Furthermore, in certain instances the polypropylene contains small amounts of ethylene in copolymers known as reactor copolymers. Thus, the grafted polypropylenes can contain minor amounts of ethylene, both as part of the ethylene-propylene segments and as polyethylene segments. The maleated polypropylene contains from about 0.01 wt.% incorporated maleic anhydride, based upon the weight of the maleated polypropylene, up to about 5 wt.%. Preferably the maleic anhydride content is from about 0.01 to about 2 wt.%, most preferably about 0.03 to about 0.2 wt.%. Unreacted polypropylene will be present in the reaction mix as will minor amounts of reaction by-products, such as decomposed free-radical initiator compounds and low molecular weight free-radical products. These by-products are substantially removed, by methods known in the art, e.g., sparging with N₂ or washing with water. Maleic anhydride cannot be left in substantial amounts in the polymer without detrimental effects on the subsequent reaction of the poly(alkenyl-cø-maleimide) with the maleated polyalkylene.

The poly(alkenyl-cø-maleimide) is formed by reacting a poly(alkenyl-co- maleic anhydride) with a mono-primary amine at temperatures from about 100° to about 300°C and at a pressure from about slightly above vacuum to about 20 atmospheres, under substantially dry conditions. The reactants are preferably dry mixed in the absence of solvents in a suitable mixing apparatus such as a Brabender mixer. Preferably, the mixer is purged with N₂ prior to charging the reactants. The primary amine may be added in a singular charge, or in sequential partial charges into the reactor containing poly(alkenyl-cø-maleic anhydride). Preferably, the primary amine is charged in a ratio of between 0.8 to 1.0 moles of amine per monomer contributed units of maleic anhydride in the poly(alkenyl-co-maleic anhydride).

Suitable primary amines include, but are not limitied to alkyl amines; alkyl benzyl amines; alkyl phenyl amines; alkoxybenzyl amines; allyl aminobenzoates; alkoxy aniline; and other linear primary amines containing from 1 to 50 carbon atoms, preferably 6 to 30 carbon atoms in the alkyl and alkoxy substituents in these primary amines. It is understood that the alkyl and alkoxy substituents on the above discussed primary amines can be linear or branched, preferably linear, and saturated or unsaturated, preferably saturated. Exemplary, but not exclusive of such amines are hexylamine, octylamine, dodecylamine, and the like.

The poly(alkenyl-cø-maleimide), prior to grafting with maleated polyalkylene, preferably has M_w of between about 10,000 and 500,000, and even more typically between about 150,000 and 450,000. The alkylene/maleimide copolymer may be prepared by any means for combining such ingredients, such as blending, milling, or internal batch mixing. A rapid and convenient method of preparation involves heating a mixture of components to a temperature of about 50° to about 290°C.

The polymers of this invention preferably are manufactured by mixing and dynamically heat-treating the components described above, namely, by melt-mixing. As for the mixing equipment, any conventional equipment such as an open-type mixing roll, closed-type Banbury mixer, closed-type Brabender mixer, extruding machine, kneader, continuous mixer, or the like is acceptable. The closed-type Brabender mixer is preferable, and mixing in an inactive gas environment, such as N₂ or Ar, is also preferable. Grafting of the maleated polyalkylene to the poly(alkenyl-co-maleimide) can be performed by addition of a grafting agent. The preferred grafting agent is a low molecular weight organic compound with at least 2 functional groups capable of crosslking the polymer. Exemplary functional groups include primary amine, secondary amine, carboxyl, formyl, and hydroxyl. A preferred grafting involves adding a polyamine, preferably an organic diamine, to a blend of maleated polyalkylene and poly(alkenyl-cø-maleimide) to partially crosslink the polyalkylene to the poly(alkenyl-cø-maleimide) through the maleate functional groups.

Suitable organic diamines or diamine mixtures containing two aliphatically or cycloaliphatically bound primary amino groups can be used as grafting agents. Such diamines include, for example, aliphatic or cycloaliphatic diamines corresponding to the formula R³(NH )₂, wherein R³ represents a C₂-C₂₀ aliphatic hydrocarbon group, a C₄-C₂₀ cycloaliphatic hydrocarbon group, a C₆-C₂o an aromatic hydrocarbon group, or a C -C ₀ N-heterocyclic ring, e.g., ethylenediamine; 1,2- and 1,3-propylene diamine; 1,4-diamino butane; 2,2-dimethy 1-1,3 - diaminopropane; 1,6-diaminohexane; 2,5-dimethyl-2,5-diaminohexane; 1,6- diaminoundecane; 1,12- diaminododecane; l-methyl-4-(aminoisopropyl)- cyclohexylamine; 3-ammomethyl-3,5,5-trimethyl-cyclohexylamine; 1,2-bis- (aminomethyl)-cyclobutane; l,2-diamino-3,6-dimethylbenzene; 1,2- and 1,4- diaminocyclohexane; 1,2-, 1,4-, 1,5-, and 1,8-diaminodecalin; l-methyl-4- ammoisopropyl-cyclohexylarriine; 4,4'-diamino-dicyclohexyl methane; 2,2'-(bis-4- amino-cyclohexyl)-propane; 3,3'-dimethyl-4,4'-dian inodicyclohexyl methane; 1,2- bis-(4-arnmocyclohexyl)-ethane; 3,3'5,5'-tetramethyl-bis-(4-aminocyclohexyl)- methane and -propane; l,4-bis-(2-arninoethyl)-benzene; benzidine; 4,4'- thiodianiline; 3,3'-dimethoxybenzidine; 2,4-diaminotoluene; diaminoditolylsulfone; 2,6-diaminopyridine; 4-methoxy-6-methyl- -phenylenediamine; dian inodiphenyl ether; 4,4'-bis(ø-toluidine); ø-phenylenediamine; methylene bis(ø-chloroaniline); bis(3,4-diaminophenyl) sulfone; diamino-phenylsulfone; 4-chloro-ø- phenylenediamine; w-aminobenzyl amine; w-phenylene diamine; 4,4'-Cι-C₆- dianiline; 4,4'-methylene-dianiline; aniline-formaldehyde resin; trimethylene glycol- di-/?-aminobenzoate; bis-(2-ammoethyl)-amine, bis-(3-aminopropyl) amine; bis-(4- ammobutyl)-amine; bis-(6-anmohexyl)-amine, and isomeric mixtures of dipropylene triamine and dibutylene triamine. Mixtures of these diamines may also be used.

Other suitable polyamines for use as grafting agents include bis- (ammoalkyl)-amines, preferably those having a total of from 4 to 12 carbon atoms, such as bis-(2-aminoethyl) amine, bis-(3-aminopropyl) amine, bis-(4-aminobutyl) amine, and isomeric mixtures of dipropylene triamine and dibutylene triamine.

Hexamethyl diamine, tetramethylene diamine, and especially 1,12-diamitιododecane are preferred.

The centipede polymers may be glassy and therefore, addition of an extender during final processing can be desired. Suitable extenders include extender oils and low molecular weight compounds or components,, such as naphthenic, aromatic, paraffinic, phthalic, and silicone oils. A preferred extender is a phthalic oil. The preferred phthalic oil is di(tridecyl)pthalate. This oil can be added in the final stages of preparation of the centipede polymer. The final centipede polymer can contain between 25 and 40% extender and therefore be a thermoreversible elastomer. After the centipede polymer is formed, it can be mixed with an epoxy polymer, preferably a hyperbranched epoxy polymer, to improve the adhesion and damping properties of the polymer gel. The term hyperbranched herein means a highly branched polymer structure with a random morphology and high resistance to crystallization. The hyperbranched epoxy polymer is formed by reacting an epoxy prepolymer with a curing agent. Epoxy polymers are typically formed by the reaction of bisphenol A and epichlorhydrin. Epichlorohydrin is reacted with a variety of hydroxy, carboxy, and amino compounds to form monomers with two or more epoxide groups, and these monomers are then used in the reaction with bisphenol A. Examples are the diglycidyl derivative of cyclohexane-1,2- dicarboxylic acid, the triglycidyl derivatives of -aminophenol and cyanuric acid, and the polylglycidyl derivative of phenolic prepolymers. Epoxidized diolefϊns are also employed. In the present invention, the preferred epoxy prepolymer is poly[(ø- cresyl glycidyl ether)-cø-formaldehyde].

A variety of coreactants can be used to cure the epoxy resins either through the epoxide or hydroxyl groups. Polyamines are the most common curing agent with reaction involving ring-opening addition of amine. Both primary and secondary amines are used with primary amines being more reactive than secondary amines. Since each N-H bond is reactive in the curing reaction, primary and secondary amine groups are bi-and mono-functional respectively. A variety of amines are used as crosslinking agents, including diethylene triamine, triethylene tetramine, 4,4'-diamino-diphenylmethane, and polyaminoamides. Preferred amines for the formation of the epoxy polymer are dodecyl amine, dibutyl arnine, octadecyl amine, and hexamemyleneimine.

A suitable epoxy polymer, preferably hyperbranced, is formed by reacting of epoxy resin with a polyamine to an extent that the system is near the gelation point, but without exceeding it. A near-gelation polymer can be formed when the degree of interchain reaction, i.e., crosslinking, between the elastomeric molecules nears or approaches the gel point of the polymeric composition. At the gel point, a gel or insoluble polymer fraction forming in a polymeric composition first becomes observable.

Theoretically, a gel corresponds to an infinite network in which polymer molecules have been crosslinked to one another to form a macroscopic molecule. The gel may then be considered one molecule. A gel generally is insoluble in all solvents at elevated temperatures under conditions where polymer degradation does not occur; the non-gel portion of the polymer, often referred to as sol, remains soluble in solvents. For present purposes, near-gelation polymers also can be referred to as near-gel polymers.

When forming a near-gelation polymer, the gel point of the polymeric composition employed to create the near-gelation polymer preferably is determined. Several techniques are known in the art for estimating the gel point of polymeric compositions. Gel point can be deteπnined experimentally by solvent extraction and other techniques described in P.J. Flory, Principles of Polymer Chemistry (1953). Gel point also can be approximated by using theoretical calculations as described in, for example, G. Odian, Principles of Polymerization, 3d ed., pp. 108-123, (1991). The polymeric composition employed to create the near-gelation polymer can be referred to as the prepolymer system.

Although gel point can be discussed in terms of a variety of parameters, determining the ratio of the weight of curative to the weight of prepolymer necessary to reach the gel point can be convenient. Thus, gel point can be represented by the weight of curative necessary to reach gelation, W_cg, over the weight of prepolymer, W_p. Likewise, the point of complete cure can be represented by the weight of curative necessary to reach complete cure, W_cc, divided by W_p. In general, therefore, the extent of any curing reaction can be represented by the weight of curative added, W_c, divided by W_p. For present purposes, extent of reaction, r, can be represented by W_c over W_p. Therefore, the extent of gelation, r_g, is r_g = W_cg/W_p, and the extent of complete cure x_∞ = W_cc W_p.

Once the gel point of the prepolymer is determined, an appropriate amount of curative can be added and reacted with the prepolymer to achieve a near-gelation polymer. When selecting an appropriate amount of curative, the gel point preferably is approached but not exceeded, although the definition of near-gelation polymer broadly includes those reaction products of curative and prepolymer that exceed the gel point without actually reaching complete cure. Thus, the weight ratio employed to create a near-gelation polymer preferably is based on E = \ (r- r_g)/ r_g | where E is the relative distance to the gel point while r and r_g are defined as above. Since E is an absolute value, E is greater than or equal to 0 and less than or equal to about 0.5, more preferably less than about 0.2, still more preferably less than about 0.1, and even more preferably no more than about 0.05. The foregoing formula involves the absolute value of a number and, therefore, the extent of the reaction (r) is a relative distance (E) both beyond and before the gel point. For example, where the gel point of a particular polymeric composition is about 0.5 parts of curative per part of prepolymer, a near-gel polymer can be obtained by reacting the polymeric composition with about 0.3 or about 0.7 parts of curative per part of the prepolymer (thus, E = |(0.3 - 0.5) / (0.5)| = 0.4 or E = |(0.7 - 0.5) / (0.5)1 = 0.4).

The prepolymer used in preparing the near-gelation polymer includes at least one functional group, preferably at least 2 functional groups, more preferably between 2 and about 10 functional groups, and even more preferably between 2 and about 5 functional groups. For present purposes, the prepolymer can be referred to as the functionalized prepolymer. The functional groups can be located at the terminal end of the prepolymer, including the initiated end of the polymer, or along the backbone of the prepolymer. Therefore, crosslinking can occur anywhere on the prepolymer chain.

Other additives known in the art can be added to the compositions of the present application. Stabilizers, antioxidants, conventional fillers, reinforcing agents, reinforcing resins, pigments, fragrances, and the like are examples of some such additives. Specific examples of useful antioxidants and stabilizers include 2- (2'-hydroxy-5'-methylphenyl) benzotriazole, nickel di-butyl-di-thiocarbamate, zinc di-butyl-di-thiocarbamate, tris(nonylphenyl) phosphite, 2,6-di-t-butyl-4- methylphenol, and the like. Exemplary conventional fillers and pigments include silica, carbon black, TiO₂, iron oxide, and the like. These compounding ingredients are incorporated in suitable amounts depending upon the contemplated use of the product, preferably in the range of 1 -350 parts of additives or compounding ingredients per 100 parts of the polymer composition.

A reinforcement is a material added to a polymer matrix to improve the strength of the polymer. Most reinforcing materials are inorganic or organic products of high molecular weight. Various examples include glass fibers, asbestos, boron fibers, carbon and graphite fibers, whiskers, quartz and silica fibers, ceramic fibers, metal fibers, natural organic fibers, and synthetic organic fibers. Other elastomers and resins are also useful to enhance specific properties like damping properties, adhesion, and processability. Examples of other elastomers and resins include adhesive-like products including Reostomer™ (produced by Riken-Vinyl, Inc.), hydrogenated polystyrene-(medium or high 3,4)-polyisoprene-polystyrene block copolymers such as Hybler™ (produced by Kurare, Inc.), polynorbornenes such as Norsorex™ (produced by Nippon Zeon, Inc.), and the like. In summary, the molded polymers produced from the blend of the present centipede polymer and epoxy polymer retain elastomeric characteristics and are useful in high damping applications.

Damping is the absorption of mechanical energy by a material in contact with the source of that energy. It is desirable to damp or mitigate the transmission of mechanical energy from, for example, a motor, engine, or power source to its surroundings. Elastomeric materials are often used for this purpose. Such materials can be highly effective in converting this mechanical energy into heat rather than transmitting it to the surroundings. This damping or conversion preferably is effective over a wide range of temperatures and frequencies commonly found near motors, automobiles, trucks, trains, planes, and the like.

The compositions of the present invention are favorably used in the manufacturing of any product in which the following properties are advantageous: a degree of softness, heat resistance, decent mechanical properties, elasticity, good adhesion, and/or high damping. The compositions of the present invention can be used in all industry fields, in particular, in the fabrication of automotive parts, tire tread rubbers, household electrical appliances, industrial machinery, precision instruments, transport machinery, constructions, engineering, medical instruments, and tire rubber formulations. Representative examples of the composition of the present invention are in the fabrication of damping materials and vibration restraining materials. These uses involve connecting materials such as sealing materials, packing, gaskets, and grommets; supporting materials, such as mounts, holders, and insulators; and cushion materials such as stoppers, cushions, and bumpers. These materials are also used in equipment producing vibration or noise and household electrical appliances, such as in air-conditioners, laundry machines, refrigerators, electric fans, vacuums, dryers, printers, and ventilator fans. These materials are also suitable for impact absorbing materials in audio equipment and electronic or electrical equipment, sporting goods, and shoes. The present invention also can be useful in any application where superior adhesion properties are important. The applications for polymers with high adhesion properties fall into two major categories, coatings and structural. Coatings applications include marine, maintenance, drum, and can coatings. Automotive primer coatings involve epoxy resins with ionic charges that allow for electrodeposition of the resin. Waterborne epoxy coatings have been developed for beer and beverage containers. Structural composites are used in the military (missile casing, tanks), aircraft (rudders, wing skins, flaps), automobiles (leaf springs, drive shafts), and pipe in the oil, gas, chemical, and mining industries.

EXAMPLES

Examples 1-4: Preparation of Epoxy Hyperbranched Polymers For Example 1, 35.0 g poly[(o-cresyl glycidyl ether)-co-formaldehyde]

(M_n~1080) was dissolved in 50 mL toluene. 4.3 g dodecyl amine was added, followed by 23.0 g dibutyl amine. The mixture was reacted at 100° to 150°C for 6 hours. The product then was heated to 200°C for 1 hour to drive off volatiles. For Example 2, 45.8 g poly[(o-cresyl glycidyl ether)-cø-formaldehyde] (M_n~1080) was dissolved in 50 mL toluene. 8.3 g octadecyl amine was added, followed by 21.05 of hexamethyleneimine. The mixture was reacted for 1 hour at 140°C, kept at ~25°C for 3 days, then heated to 160°C for 1 hour to drive off volatiles.

For Examples 3 and 4, 50.0 g poly[(o-cresyl glycidyl ether)-eø- formaldehyde] (M_n~540) was dissolved in toluene. 22.5 g octadecyl amine was added followed by 14.4 g dibutyl amine. The mixture was reacted at 140°C for 4 hours.

Example 5: Preparation of the PP-grafted Centipede Polymer To a 6L kneader-extruder (MXE-6, Jaygo Inc.) equipped with sigma blades was added 1.25 kg Isoban™ 10 poly(maleic anhydride-α t-isobutlyene) (Kuraray Ltd.) and 0.99 kg octylamine (BASF, 99% purity) at 54°C. Mixing was started with a blade speed of 25 rpm and a screw speed of 40 rpm for 5 minutes, then the temperature of the mixer was adjusted to rise to 190°C at a rate of about 3°C per minute. Mixing was continued for 2 more hours isothermally at 190°C. Then, 0.56 kg PO1015 maleated polypropylene (Exxon) was added to the mixer. Mixing was continued for another 30 minutes. Then, to the mixer was added 23 g dodecane diamine (Aldrich, 98% purity). After an additional 15 minutes, 1.4 kg di(tridecyl)phtalate oil, (C.P. Hall Co.) was added to the mixer and the temperature adjusted to 160°C. After another 2 hours, the final product was then extruded through a 6.35 mm die. The final product contained 33% DTDP oil and was a thermoreversible elastomer.

Examples 6-12: Preparation of High Damping Gels For Examples 6-8, a charge of 35 g of the product from Example 5 was added to a Brabender mixer (~55 g capacity) equipped with a roller blade and N₂ purging. The mixer was initially set to 160°C and 60 rpm. After 3 minutes, a charge of 15 g of the product from Example 1 was added to the mixer. The material was further mixed at those conditions for 17 minutes, then agitation was stopped and the mixture was removed from the mixer.

For Example 9, the procedure of Example 6 was repeated except that the epoxy polymer was the one from Example 2

For Examples 10-11, the procedure of Example 6 was repeated except that the epoxy polymers were the ones from Example 4 and Example 3, respectively. For Example 12, the procedure of Example 11 was repeated except that 25 g of the epoxy polymer from Example 3 was used.

The products of Examples 5-12 were molded into sheets and cylinder buttons at -160 °C. Ring samples were cut from these sheets for tensile measurements. The peeling test is the standard load across a 1-inch (2.54 cm) section. The details of the physical properties of the final materials are shown in Table 1.

Table 1

C.S. = Compression set at 100°C N/A = Not evaluated

Claims

We claim:

1. A polymer gel composition comprising: a. a polymer comprising a maleimide unit and an alkenyl unit, b. a crosslinking agent, c. a maleated polyalkylene, d. an epoxy polymer, and e. optionally, an extender.

2. The composition of claim 1 wherein said maleimide unit is synthesized by the reaction of maleic anhydride with monoamine.

3. The composition of any of claims 1 to 2 wherein said alkenyl unit is chosen from vinyl aromatic hydrocarbons, R'R^thylenes, and alkylvinyl ethers.

4. The composition of claim 3 wherein at least one of the following is true: said vinyl aromatic hydrocarbons comprise styrene or α-methylstyrene,

1 said R R ethylene unit is isobutylene, and said alkylvinyl ether is methylvinyl ether.

5. The composition of any of claim 1 to 4 wherein said crosslinking agent comprises a low molecular weight organic compound having 1 or more functional groups chosen from primary amine, secondary amine, carboxyl, formyl, and hydroxyl.

6. The composition of any of claims 1 to 5 wherein said maleated polyalkylene is grafted to said polymer component (a).

7. The composition of any of claims 1 to 6 wherein the monomer from which the alkylene moiety of said maleated polyalkylene is formed is at least one of ethylene and propylene.

8. The composition of any of claims 1 to 7 wherein said epoxy polymer is a hyperbranched polymer.

9. The composition of claim 8 wherein said hyperbranched polymer is the reaction product of an epoxy prepolymer and a crosslinking agent, said hyperbranched polymer having a physical state relative to the gelation point of a crosslinked polymer defined by 0 < | (r - rg /r_g \ ≤ 0.5 where r is the weight ratio of said crosslinking agent to said epoxy prepolymer and r_g is the weight ratio of said crosslinking agent to said epoxy prepolymer at the gelation point of the crosslinked polymer.

10. The composition of any of claims 1 to 9 wherein said composition exhibits tan δ values at 23°C of greater than 1.0.