COMPATIBILITY AND CRYSTALLIZATION IN POLYNETHYLENE OXIDE)-POLY(METHYLMETHACRYLATE) SEMIINTERPENETRATING POLYMER NETWORK

Differential scanning calorimetry together with dynamic mechanical ana lysis were employed to investigate the crystallinity and the miscibili ty in poly(ethylene oxide)/crosslinked poly (methyl methacrylate) semi -IPN (interpenetrating polymer networks). The crystallinity of poly(et hylene oxide) in the semi-IPN is found to depend on the crosslink dens ity of PMMA as well as the overall content of PEO. Of special interest is that an increase in the crosslink density tends to increase the cr ystallinity contrary to our expectation, indicating crystallization an d phase separation may proceed simultaneously during IPN formation. Th e investigation of glass transition behaviors with dynamic mechanical analysis suggests phase separation (i.e., there exist two amorphous ph ases: one PEO-rich phase, the other a PMMA-rich phase). (C) 1993 John Wiley & Sons, Inc.