Hydrogenation of styrene-isoprene-styrene block copolymer and its product properties

Abstract

The hydrogenation of styrene-isoprene-styrene block copolymer(SIS) was catalyzed by nickel-based catalyst, and the mechanism of catalytic reaction was studied. The conditions of catalyst preparation and hydrogenation were determined, and the structure and performance of the product were investigated. The results showed that the activity and selectivity in hydrogenation was high with nickel isooctanoate and triisobutyl aluminum as SIS hydrogenation catalysts. The conditions of the reactions were optimized with the mole ratio of aluminum to nickel was 3.0~4.0 and the mass concentration of nickel and aluminum catalyst was 25~40 g/L at aging temperature 50-70 ℃ for more than 30 min. The hydrogenation degree of polyisoprene segment in SIS was greater than 98% and the benzene ring was less than 5% with the catalyst amount 3×10-4~7×10-4 g/g for 1~2 h. The mechanical properties and aging resistance of SIS were significantly improved after hydrogenation.

Keywords

• styrene-isoprene-styrene block copolymer
• hydrogenation catalyst
• hydrogenation degree
• mechanical property
• aging resistance