Synthesis of Bismuth-Containing Polymer Films with High Refractive Index and X-ray Shielding Property by Radical Polymerization of Styrylbismuthine Derivatives
Yoshimasa Matsumura, Hiroshi Horikoshi, Kikuo Furukawa, Miyuki Miyamoto, Yoshio Nishimura, Bungo Ochiai
Abstract
Highly refractive and X-ray shielding polymer films were prepared by bulk radical copolymerization of diphenylstyrylbismuthine (MStBi) with tristyrylbismuthine (TStBi). For example, a yellow transparent film was obtained by copolymerization of MStBi and TStBi in a ratio of 70:30 (w/w). The refractive index (nD) and radiopacity of the film of these polymers are 1.72 and 1.60 μm-Al/μm-polymer, respectively. These properties are higher than those of the reported bismuth-containing polymers. The thermal stability and flexural module of the polymer films were controllable by the feed ratio of TStBi. The polymer films also exhibited high surface hardness and solvent resistance due to the rigid and cross-linked structure. The chemical and thermal stability and higher refractive index and radiopacity of the polymers suggest the potential applications for X-ray shielding of optical materials with high refractive indices.