Modification of silicon-substituted polynorbornenes by epoxidation of main chain double bonds

Abstract

Postpolymerization modification of metathesis Si-containing polynorbornenes by epoxidation of double bonds of the main chain was carried out for the first time. New polynorbornenes containing one or two side Me3Si substituents in a monomer unit and oxirane fragments in the main chain were obtained and characterized. Some features of epoxidation of polynorbornenes by 1.1-dimethyldioxirane (formed in situ) or m-chloroperbenzoic acid were studied. It was shown that m-chloroperbenzoic acid was an effective epoxidation agent, which did not affect Si−C bonds in polynorbornenes. It was found that the preparation of high-molecular-weight epoxidated polynorbornenes required one to introduce an oxidation inhibitor into the reaction mixture and to perform the reaction in toluene. Chlorine-containing solvents, such as chloroform and chlorobenzene, promoted the destruction of polynorbornenes. It was shown that the introduction of oxirane fragments into the polynorbornene main chain increased its Tg by 15−40°C.