Polysiloxanes with pendant benzimidazole units have been prepared by free radical thiol- ene coupling reactions of 2-(2-benzimidazolyl) ethanethiol and vinyl-functional polysiloxanes. The latter polymers were prepared by anionic ring opening copolymerization of 1, 3, 5, 7-tetramethyl-1, 3, 5, 7-tetravinylcyclosiloxane and 1, 3, 5- hexamethylcyclosiloxane. Copolymers with different degrees of benzimidazole ...