Transparent and Photochromic Material Prepared by Copolymerization of Bismuth(III) Methacrylate

Transparent, photochromic, and X-ray shielding polymer films were obtained by bulk radical copolymerization of bismuth­(III) methacrylate (BiMA), easily synthesized from Ph3Bi and methacrylic acid, and N,N-dimethylacrylamide (DMAA). The refractive indices and X-ray shielding abilities were increased as the increase of the bismuth content. The photochromism, coloring by UV irradiation and discoloring under ambient conditions, occurs by reversible redox between the bismuth carboxylate structure and Bi(0). The facile preparation procedure using inexpensive substances is an advantage over those of previously reported bismuth-containing polymers.