Modulated-temperature differential scanning calorimetry: 15. Crosslinking in polyurethane-poly(ethyl methacrylate) interpenetrating polymer networks

摘要

The glass transition behaviour and morphology of 70 : 30 polyurethane-poly(ethyl methacrylate) (PU-PEMA) interpenetrating polymer networks (IPNs) in which the crosslink density in both networks was systematically varied were investigated by means of modulatedtemperature differential scanning calorimetry (M-TDSC) and dynamic mechanical thermal analysis (DMTA). The observed influence on the glass transition temperature, T_g, was similar for both the M-TDSC and DMTA studies, but some substantial differences also existed. M-TDSC was more sensitive to phase separation than DMTA. On increasing the crosslink density in the first-formed PU network, the weight fraction of the interphase component increased. Higher crosslinking levels in the PEMA network had relatively little influence.