EFFECT OF UREA GROUPS ON REACTION-KINETICS OF POLYURETHANE FORMATION

Urea-containing polyurethane reaction systems, based on ethylene oxide -capped poly(propylene oxide) polyether diol, 1,4-butyldiol, uretonimi ne liquefied 4,4'-diphenylmethane diisocyanate, and a biurea compound, were used to investigate the effect of urea groups on polyurethane bu lk polymerization by using Fourier transform infrared spectroscopy. Th e biurea compound was a liquid biurea-capped poly(propylene oxide) pol yether, which can mix well with the polyurethane systems. Catalysis of urea groups was observed clearly regardless of whether organotin cata lyst was used. A catalytic mechanism was presented in this paper. (C) 1996 John Wiley & Sons, Inc.