Li Hongqiang（College of Materials Science and Engineering,South China University of Technology, Guangzhou 510640,China）　 Zeng Xingrong（College of Materials Science and Engineering,South China University of Technology, Guangzhou 510640,China）　 Guo Jianhua（College of Materials Science and Engineering,South China University of Technology, Guangzhou 510640,China）　 Wu Weiqing（Guangzhou Wang Cheong Adhesive Product Factory,Guangzhou 510800,China）　

Abstract：Epoxidation is a convenient approach to incorporate polar epoxy groups in the polybutadiene chains, which could change non-polar styrene-butadiene-styrene block copolymer (SBS) into polar epoxidized SBS (ESBS)[1]. Among the oxidants reported previously, in-situ generated peracetic acid from hydrogen peroxide and formic acid was used widely because of its low price and high security[2]. However, hydrogen peroxide and formic acid are incompatible with organic solvent in the system, which will lead to ring-opening reaction of epoxy groups and reduce epoxidation degree of ESBS. In this work, five kinds of phase transfer catalysts were used to improve epoxidation degree of ESBS and restrain ring-opening of epoxy groups.