COPOLYMERIZATION OF N-(4-VINYLPHENYL)MALEIMIDE WITH STYRENE AND N-PHENYLMALEIMIDE AND THERMAL-PROPERTIES OF THE COPOLYMERS

In order to synthesize linear polymers with crosslinkable pendant unsaturated groups, copolymerizations of N-(4-vinylphenyl)maleimide (VPMI) with N-phenylmaleimide (PMI) and styrene (St) were carried out. VPMI possesses two polymerizable carbon-carbon double bonds with different reactivities. Poly(VPMI-co-PMI)MI obtained by anionic copolymerization with potassium tert-butoxide as an initiator had both VPMI and PMI units, and the VPMI unit possessed a pendant styrene group. Poly(VPMI-co-St)St obtained by cationic copolymerization initiated by trifluoroboron etherate had both VPMI with a pendant maleimide group and St units. Thermal properties of the copolymers were examined by DSC and TGA. Every poly(VPMI-co-PMI)MI had no obvious melting point. Thermal decomposition temperatures of these copolymers were 411 approximately 434-degrees-C, which were not influenced by the composition. Poly(VPMI-co-St)St which contained more than 60 mol% St unit showed a melting point. The thermal decomposition temperature of poly(VPMI-co-St)St decreased with increasing content of St unit. Poly(VPMI-co-St)St decomposed at 384 approximately 461-degrees-C. The decomposition temperatures of these copolymers were higher than that of polystyrene.