ABSTRACT
The debut of Nylon 66, invented by W. Carothers of E.I. DuPont de Nemours & Co. in the mid-l930s, was a big stimulus to chemists for pioneering synthetic polymers. Since then, many exploratory studies in polymer synthesis have been carried out worldwide. For example, polyurethanes were first investigated by Otto Bayer and his collaborators at I.G. Farbenindustrie A.G. in Germany [1] and independently by T. Hoshino and Y. Iwakura of the Tokyo Institute of Technology in Japan [2], as well as a research group at E.I. DuPont de Nemours Co. in the United States
[3]. Similarly, polyureas were synthesized by the reaction of diisocyanate
with aliphatic diamines by the above-mentioned three research groups.
