Synthesis and polymerization of optically active N-α-methylbenzylmaleimide

Optically active N-α-methylbenzylmaleimide (MBZMI) was prepared with maleic anhydride and d-(+)-α-methylbenzylamine. The polymerizations of MBZMI were carried out with α,α′-azobisisobutyronitrile (AIBN) and n-butyllithium (n-BuLi) in tetrahydrofuran (THF). The specific rotations of the polymers obtained by AIBN and n-BuLi initiator were +11.1° to +13.0° and ?57.0° to ?89.2°, respectively. The weight-average molecular weights (M_w) for the polymers were between 4200 and 8000. Furthermore, MBZMI was copolymerized with styrene (ST) and methyl methacrylate (MMA) with AIBN in THF at 50°C to obtain optically active copolymers. The monomer reactivity ratios of MBZMI (M₁) with ST (M₂) were obtained as r₁ = 0.027, r₂ = 0.094 in the MBZMI–ST and r₁ = 0.15, r₂ = 1.54 in the MBZMI–MMA system. The Q-e values for MBZMI were Q₁ = 0.78, e₁ = 1.62. All the polymers and copolymers were found to show a weakly negative circular dichroism (CD) peak at about 250 nm and a strongly positive CD peak at about 220 nm.