Summary: The hydrogenation of a copolymer of styrene and butadiene (SBR) catalyzed by Ru(CH?CHPh)Cl(CO)(PCy3)2 was experimentally investigated within the temperature range of 120–160 °C, at Pequation/tex2gif-inf-7.gif of 300–1 200 psi, and a catalyst concentration of 10–78 × 10?6 M . Special attention was paid to minimizing the catalyst metal residue and crosslinking in the product. The results indicated that high‐quality hydrogenated SBR was achieved without crosslinking and the metal residue was less than 7 ppm without a post‐treatment.
IR spectra of the styrene–butadiene rubber before (a) and after (b) hydrogenation with the Ru(CH?CHPh)Cl(CO)(PCy3)2 catalyst were observed as reported here. The disappearance of all characteristic absorbencies of C?C (724, 910, 967, and 994 cm?1) suggests nearly quantitative hydrogenation of the C?C bonds.
