摘要 |
Carboxy-terminated prepolymers are prepared by the reaction of a diamine, preferably an aromatic diamine, or a mixture thereof with a triamine, with a carboxy anhydride such as trimellitic anhydride and a dianhydride such as bisphenol A dianhydride. The prepolymers, or functional derivatives thereof, are then reacted with a diisocyanate or diamine, or a mixture thereof with a triisocyanate or triamine, preferably an aromatic diisocyanate, to produce copolyamideimides. The products prepared using triamines or triisocyanates are crosslinked. Other products containing alkyl or alicyclic groups attached to aromatic radicals can be oxidatively crosslinked, e.g., by heating in air. |