Kinetic study of the reaction between hydroxylated polybutadienes and isocyanates. II. Reaction with 3-isocyanatomethyl-3,5,5-trimethylcyclohexylisocyanate (IPDI) and dimer diacid diisocyanate (DDI)

A comparative kinetic study of the reaction of three different hydroxylated liquid poly-butadienes (M?_n ? 3000)–R-45M, R-45HT and H-034–with 3-isocyanatomethyl–3,5,5-trimethylclohexylisocyanate (IPDI) and dimer diacid diisocyanate (DDI) was carried out in toluene solution. An analytical method was used to follow the kinetics of the reactions, at four different temperatures. In the second-order plots, a discontinuity was observed in the reaction with IPDI, in contrast to the reactions with DDI which showed straight-line plots. In all studied reactions, the R-45M polybutadiene was about twice as reactive as R-45HT and H-034. The latter hydroxylated polybutadienes (R-45HT and H-034) showed similar reactivities.