The present work comprises the synthesis of polyacilureas from terephthalic acid, isophthalic acid, terephthaldehyde, benzidine, m-phenylenediamine and p-phenylenediamine. The method used was the nucleophilic addition of amines to organic acylcyanates. Terephthaloyl dichlorides and isophthaloyl dichlorides were synthesized from terephthalic and isophthalic acids by treatment with phosphorus pentachloride. To obtain the terephthaloyl and isophthaloyl cyanates, the terephthaloyl and isophthaloyl chlorides were reacted with sodium cyanate, using dry acetone as solvent. The p-phenylene-bis (3-acryloyl) diisocyanate was obtained by reacting the p-phenylene-bis (3-acryloyl) chloride with sodium cyanate in dry acetone. A series of polyacilureas was prepared via nucleophilic addition of different amines to the acyl isocyanates. The final products synthesized were: poly- [N-terephthaloyl-N '- (4,...