A polycarbonate resin, containing in the polymer chain at least one divalent moiety of the formula: ##STR1## wherein E is selected from the group consisting of alkylene containing from 1 to 15 carbon atoms, inclusive, and halogen-substituted alkylene containing from 1 to 15 carbon atoms, inclusive, a is an integer of 0 or 1 and R' is hydrogen or hydrocarbyl or halogen substituted hydrocarbyl amenable to beta elimination upon thermal degradation.