RADIOPAQUE COPOLYMERS OF STYRYLDIPHENYLBISMUTH VINYLBENZYLPHOSPHONATEAND METHYL-METHACRYLATE

Styryldiphenylbismuth (SDB) has been copolymerized with vinylbenzylpho sphonate ester (VBP) and methyl methacrylate (MMA) producing highly ra diopaque copolymers and terpolymers. The phosphoryl ester groups were also converted to phosphonic acids and the polymers were characterized . Thermal analysis of the co- and terpolymers yielded single glass tra nsition temperatures in the range 60-100 degrees C. Poly(styryldipheny lbismuth vinylbenzylphosphonate ester) copolymer is thermally stable u p to 255 degrees C and degrades at ca. 285 degrees C, producing bismut h crystallites within the partially degraded polymer matrix. Radiopaci ties of the polymers were compared to aluminum standards and were foun d to be proportional to the bismuth contents. It was found that ca. 16 mol% (or 31.6 wt%) of styryldiphenylbismuth in the terpolymer of SDB, VBP, and MMA has double the radiopacity of aluminum.