Preparation of Epoxy Resins Containing Ether Ether Ketone Unit and Their Thermal Properties

Epoxy resins are among the most important thermosetting polymers and have wide use as structural adhesives and matrix resins for fiber composites. Their cured resins have one drawback: they are brittle and have poor resistance to crack propagation. Various kinds of engineering thermo-plastics such as poly(ether sulfone)s,1-3 poly(ether imide)s,4-7 poly(aryl ether ketone)s8-10 and poly(phenylene oxide)11,12 have been examined as modifiers. They were found to be less effective owing to the poor interfacial bonding between the two uncompatibilized phases in the cured resin. There is a need for toughened epoxy resin having an engineering thermoplastic unit in the main chain, which maintains a toughness without phase separation at the elevated tempera-ture. In this report, 4,4'-bis(p-dihydroxyphenoxy)benzophenone diglycidyl ether (DHBPDGE) containing an ether-ether-ketone (EEK) unit was newly prepared and the thermal properties of epoxy system using 4,4'-diaminodiphenylether (DDE), 4,4'-diaminodiphenylmethane (DDM) and 4,4'-diaminodiphenylsulfone (DDS) were examined by DSC an