p of the dicarboxylic polyfunctional compound, which group is unsubstituted or inertly substituted, optionally including ethylenic or other unsaturation such as acrylic or a, b -ethylenically unsaturated acids or derivatives thereof, but preferably alkylene, alkylene ether and/or alkylene ester group (more preferably an alkylene group) of from 1 to about 12 carbon atoms, more preferably of from ab