Polycarbodiimides and their derivatives

Several polycarbodiimides were prepared by the solution condensation of aromatic and aliphatic diisocyanates in the presence of 1‐phenyl‐3‐methyl‐3‐phospholene‐1‐oxide. In general, the polymers had high melting temperatures and were insoluble in all solvents examined. Water, hydrogen sulfide, alcohols, or primary amines, were reacted with the polycarbodiimide prepared from methylene bis(4‐phenyl isocyanate) to give polyureas, polythioureas, poly‐O‐alkylpseudoures, and polyguanidines respectively.