Epoxy-terminated phenolphthalein poly(ether ether ketone) reactive oligomers: cure with 4,4′-diaminodiphenylether

Summary Epoxy-terminated phenolphthalein poly(ether ether ketone)s (E-PEKs) of number average molecular weights from 1,200 to 8,400 were cured with 4,4-diaminodiphenylether (DDE). The cure kinetics was studied by DSC. The values obtained for the activation energy of the cure reaction were comparable to those reported for the curing of epoxy systems. The attained glass transition temperature was dependent on the cure temperature. The properties of both the neat oligomer and the fully crosslinked polymer were a function of the initial molecular weight of the oligomer. For molecular weight (¯Mn) varying between 1,200–4,500 the glass transition temperature of the fully crosslinked polymer (Tgoo) varies between 206–183 °C as a result of decreasing crosslinked density.