Phase separation during crosslinking of epoxy resin/poly(ethylene oxide) blends

Poly(ethylene oxide) (PEO) was found to be miscible with uncured epoxy resin of DGEBA type (ER) as shown by the existence of a single glass transition temperature (Tg) in each blend. However, PEO with ¯Mn = 20,000 was judged to be immiscible with the highly aminecross linked ER. It was observed that the phase separation in the ER/PEO blends occurred as the crosslinking progressed. This is considered to be due to the dramatical change in the chemical and physical nature of ER during the crosslinking.