POLYMERIZATION OF POLYURETHANE AND VINYL-ESTER RESIN INTERPENETRATINGPOLYMER NETWORKS DURING REACTION INJECTION-MOLDING PROCESS

The reaction kinetics of polyurethane and vinyl ester resin interpenet rating polymer network (PU/VER SIN) during reaction injection moulding (RIM) polymerization has been on-line monitored by using a Fourier tr ansform infrared (FTi.r.) spectrometer linked up with a portable mini- RIM machine. For using VER, in which the pendent hydroxyl groups were capped with acetyl groups to minimize the possibility of chemical bind ing between the two networks, the two pairs of reactants interfere wit h each other during the course of synthesis. The unusual polymerizatio n kinetics behaviour observed could be correlated well with the change of morphology of the system. For using VER containing pendent hydroxy l groups, the occurrence of chemical binding between the two networks could greatly affect the reaction kinetics and morphology of the syste m. (C) 1997 Elsevier Science Ltd.