论文部分内容阅读
ATRP, as one of the most successful controlled/‘‘living’’ radical polymerization techniques, has been applied to a large variety of monomers including styrenes,(meth)acrylates,(meth)acrylamides,acrylonitrile, and vinyl acetate. However, ATRP of isoprene still remains a challenge due to poor solubility of copper catalysts in isoprene and low chain propagation rate constant of the monomer. In this work,Cu Br/2,2’-bipyridine was found to effectively mediate ATRP of isoprene at 100 °C, 130 °C, and 150 °C with ethyl 2-bromopropionate as an initiator. The polymerizations proceeded smoothly and reached 48.1%,53.3%, and 71.0% conversions, respectively, in 72 h, producing polyisoprenes with molecular weights close to theoretical values and relatively narrow distributions. A block copolymer of polystyrene-bpolyisoprene was prepared using Cu Br/2,2’’-bipyridine as a catalyst and polystyrene as a macroinitiator.The ~1H NMR and ~(13)C NMR analysis of polyisoprene indicated that the polymer had 88.8% 1,4-addition structure and 63.9% of the polymer backbone units were in trans-configuration.
ATRP, as one of the most successful controlled / ’’ living ’’ radical polymerization techniques, has been applied to a large variety of monomers including styrenes, (meth) acrylates, (meth) acrylamides, acrylonitrile, and vinyl acetate. However, ATRP of this isoprene still remains a challenge due to poor solubility of copper catalysts in isoprene and low chain propagation rate constant of the monomer. In this work, Cu Br / 2,2’-bipyridine was found to be effectively mediate ATRP of isoprene at 100 ° C , 130 ° C, and 150 ° C with ethyl 2-bromopropionate as an initiator. The polymerizations proceeded smoothly and reached 48.1%, 53.3%, and 71.0% conversions, respectively, in 72 h, producing polyisoprenes with molecular weights close to theoretical values A block copolymer of polystyrene-bpolyisoprene was prepared using Cu Br / 2,2 ’’ - bipyridine as a catalyst and polystyrene as a macroinitiator. ~ 1H NMR and ~ (13) C NMR analysis of polyisoprene indicated that the polymer h ad 88.8% 1,4-addition structure and 63.9% of the polymer backbone units were in trans-configuration.