Synthesis and radical polymerization of bifunctional maleimides with different functional reactivities

Three bifunctional N-phenylmaleimide derivatives, N-[4-(2-hydroxy-3-methacryloyloxy propyloxycarbonyl)phenyl]maleimide (GMAPMI, 1), N-(4-methacryloyloxyphenyl) maleimide (MAPMI, 2) and 4-(4-maleimidobenzoyloxy)styrene (MIBOSt, 3) having radically polymerizable maleimide and vinyl groups together have been synthesized and polymerized. Polymerizations of the bifunctional maleimide monomers were carried out using a radical initiator at 55 degrees C and the results were compared with those obtained by self-polymerization in the absence of initors. All of the polymers obtained were insoluble in organic solvents owing to cross-linking between different functional groups. The reactivity for homopolymerization of monomer 3 is higher than that of monomers 1 and 2 because the styryl moiety of monomer 3 has better electron-donor strength than the methacrylate moiety. Under the same conditions, GMAPMI was copolymerized with N-vinyl-2-pyrrolidone and styrene as an electron-donor to give higher conversions by electron-donor/acceptor polymerization in which the maleimide moiety of GMAPMI mainly involved as an electron acceptor.