Rubber-Modified Epoxies. II. Morphology, Transitions, and Mechanical Properties

摘要

The mechanical properties of two fully cured rubber-modified epoxy systems, each with varying morphologies and maximum glass transition temperatures developed from different cure conditions, have been investigated versus temperature (-90 to 140 C) using the neat system (glass transition temperature = 167 C) as control. The mechanical properties of the amino-terminated rubber-modified system were more sensitive to cure history than those of the prereacted carboxyl-terminated rubber-modified system. The improvement of fracture energy (G sub IC) at a low strain rate for a rubber-modified epoxy system depends on both the volume fraction of the dispersed phase and the inherent ductility of the matrix, the latter being related to glass transition temperature.