Polyisocyanate polyaddition polymers and a process for their preparation

Synthetic polymers and a process for their preparation by a polyisocyanate polyaddition reaction are described. Synthetic polymers are provided by the reaction of a polyisocyanate with substantially an equivalent amount of an oligomeric para-, meta- or di-meta-aminobenzoic acid ester or amide having the formulawherein n is an integer of from 2 to 4; each x is one or two; each benzoyl nucleus is para-, meta- or di-meta- amino-substituted; each Z is -0- orand G is an n-valent radical which may be obtained by the removal of hydroxyl or amino groups from an n-valent oligomeric polyol or polyamine having a molecular weight of from about 400 to about 6,000. Useful synthetic polymeric products can be simply and effectively provided by reaction of the polyisocyanate and the oligomeric aminobenzoic acid ester or amide reactants without the requirement of additional curative or chain-extending agents.