Unsaturated epoxides as coupling agents for carbon fibers and unsaturated matrix resins

Claim 2

A composite structure which is a cured admixture comprising (a) carbon fibers, (b) an unsaturated matrix resin and (c) an unsaturated epoxide bifunctional coupling agent having the general structural formula: ##STR3## wherein X is a radical selected from the group consisting of ##STR4## and divalent alkyl, aryl, aralkyl and alkaryl radicals containing up to 20 carbon atoms, and R is an unsaturated radical selected from the group consisting of (a) ethylenically unsaturated C 1 -C 4 aliphatic radicals, (b) an aryl radical containing an ethylenically unsaturated C 1 -C 4 aliphatic substituent (c) the alpha - terpinyl radical, (d) the gamma - terpinyl radical and (e) the abietyl radical.

Claim 3

The composite structure of claim 1 wherein said bifunctional coupling agent is an unsaturated glycidyl ether.

Claim 4

The composite structure of claim 2 wherein said bifunctional coupling agent is allyl glycidyl ether.

Claim 5

The composite structure of claim 1 wherein said bifunctional coupling agent is an unsaturated glycidyl ester.

Claim 6

The composite structure of claim 4 wherein said bifunctional coupling agent is glycidyl acrylate.

Claim 7

The composite structure of claim 1 wherein said unsaturated matrix resin is an unsaturated polyester resin.

Claim 8

The composite structure of claim 6 wherein said unsaturated polyester resin is a styrene modified unsaturated polyester derived from isophthalic acid, maleic anhydride and propylene glycol.

Claim 9

A composite structure which is a cured admixture comprising (a) carbon fibers, (b) poly(arylacetylene) matrix resin system and (c) an unsaturated epoxide bifunctional coupling agent having the general structural formula: ##STR5## wherein X is a radical selected from the group consisting of ##STR6## and divalent alkyl, aryl, aralkyl and alkaryl radicals containing up to 20 carbon atoms, and R is an ethylenically unsaturated radical.

Claim 10

A composite structure which is a cured admixture comprising (a) carbon fibers, (b) poly(arylacetylene) matrix resin system and (c) an unsaturated epoxide bifunctional coupling agent having the general structural formula: ##STR5## wherein X is a radical selected from the group consisting of ##STR6## and divalent alkyl, aryl, aralkyl and alkaryl radicals containing up to 20 carbon atoms, and R is an ethylenically unsaturated radical.

Claim 11

The composite structure of claim 8 wherein said poly(arylacetylene) matrix resin system comprises (1) a prepolymer of at least one polyacetylenically substituted aromatic compound, said prepolymer having a number average molecular weight from about 900 to about 12,000, a ratio of aromatic protons to olefinic protons greater than about 2.4 and containing from about 5 to about 20% acetylenic groups by weight of the prepolymer, with (2) from about 2 to about 200%, by weight of the prepolymer, of at least one aromatic organic compound containing at least two six-membered aromatic rings, said rings being condensed with each other or coupled with each other directly or through a methylene, dimethylmethylene, ethylene or vinylene group, said compound or mixtures thereof containing no crystalline organic phase at 220° C., having a viscosity of less than 20 centipoises at 220° C. and containing no more than 5% of material volatile at 240° C.

Claim 12

The composite structure of claim 9 wherein the prepolymer comprises a polymer of a diethynylbenzene.

Claim 13

The composite structure of claim 10 wherein the polymer of a diethynylbenzene is a copolymer of a diethynylbenzene and diphenylbutadiyne.

Claim 14

The composite structure of claim 10 wherein the polymer of a diethynylbenzene is a copolymer of a diethynylbenzene and phenylacetylene.

Claim 15

The composite structure of claim 10 wherein the aromatic organic compound is anthracene.

Claim 16

The composite structure of claim 10 wherein the aromatic organic compound is the complex mixture of high boiling aromatic compounds present in high boiling fractions of coal tar pitch.

Claim 17

The composite structure of claim 8 wherein said bifunctional coupling agent is an unsaturated glycidyl ether.

Claim 18

The composite structure of claim 15 wherein said bifunctional coupling agent is allyl glycidyl ether.

Claim 19

The composite structure of claim 8 wherein said bifunctional coupling agent is an unsaturated glycidyl ester.

Claim 20

The composite structure of claim 17 wherein said bifunctional coupling agent is glycidyl acrylate.

Claim 21

A process of improving the adhesion between carbon fibers and an ethylenically unsaturated matrix resin in a carbon fiber reinforced composite structure comprising incorporating into a mixture of said matrix resin and carbon fibers, an unsaturated epoxide bifunctional coupling agent having the general structural formula: ##STR7## wherein X is a radical selected from the group consisting of ##STR8## and divalent alkyl, aryl, aralkyl and alkaryl radicals containing up to 20 carbon atoms, and R is an unsaturated radical selected from the group consisting of (a) ethylenically unsaturated C 1 -C 4 aliphatic radicals, (b) an aryl radical containing an ethylenically unsaturated C 1 -C 4 aliphatic substituent, (c) the alpha - terpinyl radical, (d) the gamma - terpinyl radical, (e) the abietyl radical and curing the resulting mixture.

Claim 22

A process of improving the adhesion between carbon fibers and an ethylenically unsaturated matrix resin in a carbon fiber reinforced composite structure comprising incorporating into a mixture of said matrix resin and carbon fibers, an unsaturated epoxide bifunctional coupling agent having the general structural formula: ##STR7## wherein X is a radical selected from the group consisting of ##STR8## and divalent alkyl, aryl, aralkyl and alkaryl radicals containing up to 20 carbon atoms, and R is an unsaturated radical selected from the group consisting of (a) ethylenically unsaturated C 1 -C 4 aliphatic radicals, (b) an aryl radical containing an ethylenically unsaturated C 1 -C 4 aliphatic substituent, (c) the alpha - terpinyl radical, (d) the gamma - terpinyl radical, (e) the abietyl radical and curing the resulting mixture.

Claim 23

The process of claim 19 wherein said bifunctional coupling agent is an unsaturated glycidyl ether.

Claim 24

The process of claim 20 wherein said bifunctional coupling agent is allyl glycidyl ether.

Claim 25

The process of claim 19 wherein said bifunctional coupling agent is an unsaturated glycidyl ester.

Claim 26

The process of claim 22 wherein said bifunctional coupling agent is glycidyl acrylate.

Claim 27

The process of claim 19 wherein said unsaturated matrix resin is an unsaturated polyester resin.

Claim 28

The process of claim 24 wherein said unsaturated polyester resin is a styrene modified unsaturated polyester derived from isophthalic acid, maleic anhydride and propylene glycol.

Claim 29

A process of improving the adhesion between carbon fibers and an ethylenically unsaturated matrix resin in a carbon fiber reinforced composite structure comprising (1) modifying the surface of said carbon fibers by treatment thereof with an unsaturated epoxide bifunctional coupling agent having the general structural formula: ##STR9## wherein X is a radical selected from the group consisting of ##STR10## and divalent alkyl, aryl, aralkyl and alkaryl radicals containing up to 20 carbon atoms, and R is an unsaturated radical selected from the group consisting of (a) ethylenically unsaturated C 1 -C 4 aliphatic radicals, (b) an aryl radical containing an ethylenically unsaturated C 1 -C 4 aliphatic substituent, (c) the alpha - terpinyl radical, (d) gamma - terpinyl radical and (e) the abietyl radical, (2) admixing the surface modified carbon fibers and an ethylenically unsaturated matrix resin, and (3) curing the resulting admixture.

Claim 30

A process of improving the adhesion between carbon fibers and an ethylenically unsaturated matrix resin in a carbon fiber reinforced composite structure comprising (1) modifying the surface of said carbon fibers by treatment thereof with an unsaturated epoxide bifunctional coupling agent having the general structural formula: ##STR9## wherein X is a radical selected from the group consisting of ##STR10## and divalent alkyl, aryl, aralkyl and alkaryl radicals containing up to 20 carbon atoms, and R is an unsaturated radical selected from the group consisting of (a) ethylenically unsaturated C 1 -C 4 aliphatic radicals, (b) an aryl radical containing an ethylenically unsaturated C 1 -C 4 aliphatic substituent, (c) the alpha - terpinyl radical, (d) gamma - terpinyl radical and (e) the abietyl radical, (2) admixing the surface modified carbon fibers and an ethylenically unsaturated matrix resin, and (3) curing the resulting admixture.

Claim 31

The process of claim 26 wherein said bifunctional coupling agent is an unsaturated glycidyl ether.

Claim 32

The process of claim 27 wherein said bifunctional coupling agent is allyl glycidyl ether.

Claim 33

The process of claim 26 wherein said bifunctional coupling agent is an unsaturated glycidyl ester.

Claim 34

The process of claim 29 wherein said bifunctional coupling agent is glycidyl acrylate.

Claim 35

The process of claim 26 wherein said unsaturated matrix resin is an unsaturated polyester resin.

Claim 36

The process of claim 31 wherein said unsaturated polyester resin is a styrene modified unsaturated polyester derived from isophthalic acid, maleic anhydride and propylene glycol.

Claim 37

Carbon fibers having the surface thereof modified with an unsaturated epoxide bifunctional coupling agent having the general structure formula: ##STR11## wherein X is a radical selected from the group consisting of ##STR12## and divalent alkyl, aryl, aralkyl and alkaryl radicals containing up to 20 carbon atoms, and R is an unsaturated radical selected from the group consisting of (a) ethylenically unsaturated C 1 -C 4 aliphatic radicals, (b) an aryl radical contining an ethylenically unsaturated C 1 -C 4 aliphatic substituent, (c) the alpha - terpinyl radical, (d) the gamma - terpinyl radical and (e) the abietyl radical.

Claim 38

Carbon fibers having the surface thereof modified with an unsaturated epoxide bifunctional coupling agent having the general structure formula: ##STR11## wherein X is a radical selected from the group consisting of ##STR12## and divalent alkyl, aryl, aralkyl and alkaryl radicals containing up to 20 carbon atoms, and R is an unsaturated radical selected from the group consisting of (a) ethylenically unsaturated C 1 -C 4 aliphatic radicals, (b) an aryl radical contining an ethylenically unsaturated C 1 -C 4 aliphatic substituent, (c) the alpha - terpinyl radical, (d) the gamma - terpinyl radical and (e) the abietyl radical.

Claim 39

Carbon fibers of claim 33 wherein said bifunctional coupling agent is an unsaturated glycidyl ether.

Claim 40

Carbon fibers of claim 34 wherein said bifunctional coupling agent is allyl glycidyl ether.

Claim 41

Carbon fibers of claim 33 wherein said bifunctional coupling agent is an unsaturated glycidyl ester.

Claim 42

Carbon fibers of claim 36 wherein said bifunctional coupling agent is glycidyl acrylate.