The Preparation of Poly(ethylene N,N′-Disubstituted Ureas) by the 1,4-Addition Type Ring-opening Polymerization of 2-Imino-1,3-oxazolidines

Various 2-imino-1,3-oxazolidines have been prepared from β-chloroethylureas or from ethanolamines and cyanogen bromide. N,N′-Disubstituted 2-imino-1,3-oxazolidines give poly(ethylene N,N′-disubstituted ureas) by 1,4-addition type ring-opening polymerization in the presence of a cationic catalyst such as boron trifluoride etherate. On the other hand, 2-unsubstituted imino-1,3-oxazolidines polymerize with difficulty and give polymers with low melting temperatures.