X-Ray Shielding Polymer Based on Sequential Polycondensation of BiPh and Carboxylic Acids and Radical Polymerization.

Transparent X-ray shielding polymer films were developed by bulk photo copolymerization of in situ prepared bismuth carboxylate prepolymers with polymerizable exomethylene moieties and ,-dimethylacrylamide (DMAA). The bismuth-containing prepolymers were prepared via the polycondensation of BiPh, 2-octenylsuccinic acid (OSA), and itaconic acid (IA) bearing an exomethylene group for polymerization. OSA was a chain extender by intermolecular condensation and a stopper by intramolecular cyclization to inhibit cross-linkage. The resulting photocured films exhibit high visible-light transparency and high , reaching 1.57. The X-ray shielding ability increased with the bismuth content and reached an aluminum equivalent of 0.80.