Abstract The present invention relates to a method of producing low density polydiene resins having high yield strengths and the products thereof. In particular a polydiene resin, such as dihydroxyl terminated 1,2-polybutadiene is reacted at room temperature with an organic chain extender, such as hexamethylene -1,6-diisocyanate, and a graft comonomer such as N-vinyl-2pyrrolidone in the presence of a peroxide free radical initiator, such as O,O''-bis(t-butyl peroxy) diisopropylbenzene, whereby an elastomeric material having the peroxide and a graft comonomer dispersed therethrough is produced. At a subsequent period of time, the elastomeric material can be exposed to elevated temperatures whereupon the elastomer is cured to a low density resin having a high yield strength.
A thermosetting polydiene resin comprising: an elastomeric material which is the reaction product at ambient temperatures of (A) a dihydroxy polydiene prepolymer having (1) two terminal hydroxy groups and (2) a predominate amount of vinyl groups on alternate carbon atoms on the polydiene backbone, with (B) an organic chain extender which is a diisocyanate, and with (C) a graft comonomer selected from the group consisting of N-vinyl-2-pyrrolidone, N-vinyl-3-pyrrolidone, N-vinylcarbazole, N-vinylimidazole, N-vinylpyridine, courmarone, indene and mixtures thereof, in the presence of (D) a peroxide free radical initiator, provided that the peroxide and the graft comonomer are dispersed through the elastomeric material substantially unreacted.
Claim 2
Dependent Claim
23 words
A process according to claim 1 wherein the cyclic graft comonomer is selected from the group consisting of N-vinyl-2-pyrrolidone, N-vinyl-3-pyrrolidone, and mixtures thereof.
Claim 3
Dependent Claim
24 words
A thermosetting resin according to claim 2 wherein the cyclic graft comonomer is selected from the group consisting of N-vinyl-2-pyrrolidone, N-vinyl-3-pyrrolidone, and mixtures thereof.