Synthesis and polymerization of N-(4-ethynylphenyl)maleimide as a novel monomer with two polymerizable and modifiable groups

In this study, a novel monomer molecule, N-(4-ethynylphenyl)maleimide (EPMI) with two polymerizable and modifiable groups (ethynyl and maleimido) was synthesized. Both radical and anionic polymerizations of EPMI at the vinylene group in a maleimide moiety yielded poly[N-(4-ethynylphenyl)maleimide] (PEPMI) with pendent ethynyl groups. The yields of PEPMI were 84.5% and 80.5% from an anionic initiator potassium tert-butoxide at − 60 °C for 3 h and radical initiator 2,2′-azobisisobutyronitrile at 60 °C for 24 h, respectively. EPMI was also polymerized by selective coordination polymerization of the ethynyl moiety with [(nbd)RhCl]2 catalyst to produce poly[(4-maleimido)phenylacetylene] (PMAPA) bearing a poly(phenylacetylene) type main chain with pendent maleimido groups. On the contrary, no polymeric material was obtained with cationic initiators.