Photosensitized copolymerization of optically active N‐l‐menthylmaleimide with styrene and methyl methacrylate

Photosensitized copolymerization of optically active N‐l‐menthylmaleimide (NMMI) with styrene (Sty) and methyl methacrylate (MMA) was carried out in tetrahydrofuran (THF) at 30°C with benzoyl peroxide (BPO). The monomer reactivity ratios for the copolymerization of NMMI (M2) with Sty (M1) and MMA (M1) were r1 = 0.08 ± 0.10, r2 = 0.20 ± 0.05 and r1 = 2.85 ± 0.06, r2 = 0.07 ± 0.06, respectively. Copoly‐MMA–NMMI and poly‐NMMI showed positive circular dichroism(CD) curves of equal intensity and shape over the wavelength region from 230 to 270 nm; copoly‐Sty–NMMI also showed a positive CD curve which was similar in shape but was different in intensity from that of poly‐NMMI. The correlation between monomer unit ellipticity of the copolymers and their composition would suggest the alternating and stereoregular copolymerization of NMMI with Sty.