Phase separation time/temperature dependence of some thermoplastics-modified thermosetting systems

Abstract

The phase separation processes of various thermoplastics-modified thermosetting systems which show upper critical solution temperature (UCST) or lower critical solution temperature (LCST) were studied with emphasis on the temperature dependency of the phase separation times. It was found that the phase separation time-temperature relationship follows the Arrhenius equation. The cure-induced phase separation activation energy E a (ps) generated from the equation is independent of the method used to measure phase separation time. In our experimental ranges it is found that E a (ps) is independent of the thermoplastic (TP) content,TP molecular weight and curing rate but it varies with the cure reaction kinetics and the chemical environments of the systems.

Rheological study of the SAN modified epoxy–DDM system: relationship between viscosity and viscoelastic phase separation

“…Several studies have been reported. [6][7][8] Pascault et al gave a clear relationship between rheological prole and phase separation in polyetherimide modied epoxy systems; they observe an increase in complex viscosity for phase inverted blends. 9 Kim and Char observed an early increase in viscosity due to the phase separation of thermoplastic from the thermoset matrix followed by a decrease due to the destruction of the phase, before the abrupt viscosity increase due to epoxy-amine reaction.…”