Vinylsilane Inducing Selective Chain Transfer Reactions: An Effective Method for the Preparations of Isotactic Polystyrene Based Stereoregular Diblock Copolymers

• Main Authors: Yung-cheng Mao, 毛永成
• Other Authors: none
• Format: Others
• Language: zh-TW
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/99426980024587906568

碩士 === 國立中正大學 === 化學工程所 === 98 === In this research, we demonstrate that vinylsilane end-capped isotactic poly-4-methylstyrene (iPMS) can be selectively produced by conducting the isospecific polymerization of 4-methylstyrene in the presence of dimethylphenylvinylsilane (DMPhVS) using Ni(acac)2/MAO as the catalyst. The resulting vinylsilane end-capped iPMS can be used as the end-functionalized stereoregular prepolymer for the preparations of structurally well-defined stereoregular diblock copolymers, which are unable to be parepared by prior methods. Thus, the DMPhVS-capped iPMS was allowed to undergo desilylation reaction and hydroboration oxidation to provide the hydroxy-capped iPMS as the end-functionalized prepolymer for the preparations of stereoregular diblock copolymers. Using this new synthetic route, iPMS-b-PLLA has been prepared by conducting ring opening polymerization (ROP) of L-lactide using the hydroxy-capped iPMS as the macroinitiator. The diblock copolymers prepared by this new synthetic method have been found to possess well-defined chemical structures (uniform block lengths and narrow ranges of molecular weight distribution) to be used in the self-assembly studies for displaying consistent nanomorphologies as revealed by SAXS and TEM analyses.