Abstract
The organic-inorganic hybrid polymer network was obtained by platinum-catalyzed hydrosilylation as the crosslinking reaction, based on an acrylic polymer containing alkenyl group and phenylmethylhydrogenpolysiloxane (PMHS). The mechanism in the crosslinking reaction and the film properties were investigated. It was found by 29Si NMR analysis of the products of acetate containing alkenyl group/PMHS (as the model reactions) that two reactions occurred, producing reactions of hydrosilylation and silylesterification. In the cases of 2-methyl-2-propenyl acetate/PMHS and 3-methyl-3-butenyl acetate/PMHS, hydrosilylation selectively occurred. The radical polymerization of 3-methyl-3-butenyl methacrylate (3M3BMA) progressed without gelation, and poly (3M3BMA) having a suitable molecular weight was obtained. The thermally cured film of poly (3M3BMA) and PMHS provided excellent alkali resistance (0.1 N KOH ethyl alcohol solution). The tendency that the dynamic glass transition temperature Tg increased with increasing the crosslinking density ρ (E′) of the films was expressed by the equation Tg=K1 (log ρ (E′) + log K2), where K1 and log K2 were constant: 70 and 3.0, respectively.
