KINETICS OF THE STEP-GROWTH POLYMERIZATION OF EPOXIDE IN THE PRESENCEOF THE LINEAR POLYURETHANE - EFFECT OF THE PHASE-SEPARATION OF COMPONENTS

The process of formation of polymer blends based on linear polyurethan es (PU) and hardening polyepoxide (PEp) both without and with addition of epoxy-urethane copolymer (EpUC) was studied. Correlation between t he phase separation initiation time and the degree of conversion of ep oxy groups was ascertained. It was shown that the process of formation of PU/PEp blends involves an extremal character of variation of the d egree of conversion of epoxy groups and of the phase separation initia tion time with the composition of the system. The addition of EpUC to the hardening system caused a substantial change of the phase separati on initiation time and changed the physical and mechanical characteris tics of the resulting material. The influence of the molecular weight of PU and various epoxy resin hardeners on dhe character of phase sepa ration and other parameters of a hardening system was studied.