Vinyl polybutadiene bisimide copolymers

Vinyl polybutadiene bisimide copolymers which are peroxide curable are provided by two methods of formation. In the first method a bisimide cross-linked vinyl polybutadiene prepolymer is formed by combining a high vinyl content polybutadiene providing pendant vinyl groups with a bisimide in the presence of a first free radical initiating catalyst. The resultant cross-linked prepolymer is cured to a hard resin by the formation of additional cross-linkages through the pendant vinyl groups by heating the prepolymer to a temperature of at least about 300 DEG F. in the presence of a second free radical initiating catalyst. The second method discloses a method wherein the bisimide cross-linkages are formed in situ. In the second method, a high vinyl content polybutadiene providing pendant vinyl groups is reacted with maleic anhydride to form a maleic anhydride vinyl polybutadiene adduct. The adduct is subsequently combined with an aromatic polyamine and a free radical initiating catalyst. The mixture is heated to about 250 DEG F. to form a prepolymer having bisimide cross-linkages between the vinyl polybutadiene backbone segments. By continuing to heat the prepolymer to at least about 300 DEG F. still in the presence of the free radical initiating catalyst, the prepolymer is cured to a hard resin by the formation of cross-linkages between the pendant vinyl groups.