Photo-copolymerization of methacryloyl-L-valine methyl ester,methacryloyl-D-valine methyl ester,and maleic anhydride

Photocopolymerization of methacryloyl-L -valine methyl ester (L-MAVM), methacryloyl-D -valine methyl ester (D-MAVM) and maleic anhydride (MAn) was carried out in dioxane at 25°C without initiator at an initial total concentration of the three monomers of 1 mole/1.; the molar ratio of MAn in the feed to the sum of L- and D-MAVM was 1 : 1 in all cases. The copolymer with a 1 : 1 molar ratio of MAVM and MAn was always obtained regardless of the feed molar ratio of L- and D-MAVM. The circular dichroism (CD) spectra of the copolymer before and after hydrolysis showed a linear relationship between the monomer unit ellipticity at 222 nm and the molar feed ratio of L- and D-MAVM and suggested the induction of an asymmetric center into the polymer main chain. The results also indicated that the configuration of the induced asymmetric carbon atoms would be arranged according to that of fed MAVM monomer.