利用席佛碱催化体系催化二氧化碳(CO2)和环氧氯丙烷(ECH)共聚反应,合成出新型环状碳酸酯(ECHCO2)。利用红外光谱、核磁等方法对产物进行了表征。结果表明,最优化的试验温度是60℃,这一催化剂体系催化的活性高达920 polymer/(mol Co h),...利用席佛碱催化体系催化二氧化碳(CO2)和环氧氯丙烷(ECH)共聚反应,合成出新型环状碳酸酯(ECHCO2)。利用红外光谱、核磁等方法对产物进行了表征。结果表明,最优化的试验温度是60℃,这一催化剂体系催化的活性高达920 polymer/(mol Co h),并且有较高的选择性,高达99%。展开更多
The block coordination copolymerization of isoprene （Ip） with epichlorohydrin （ECH）has not been reported yet. Deore once studied the anionic type copolymerization ofdiene with ethylene oxide by naphthalene-potassi...The block coordination copolymerization of isoprene （Ip） with epichlorohydrin （ECH）has not been reported yet. Deore once studied the anionic type copolymerization ofdiene with ethylene oxide by naphthalene-potassium catalyst and obtained the solid polymerelectrolytes. Based on the coordination polymerization of Ip and ring-openingpolymerization of alkene oxide by rare earth catalysts, we first studied the blockcopolymerization of Ip and ECH in the presence of rare earth coordination catalysts:RE(P<sub>204</sub>)<sub>3</sub>-Al （i-Bu）<sub>3</sub>-halide. The block copolymer which has high molecular weight with展开更多
The monomer-activated anionic ring-opening copolymerization (AROP) of ethylene oxide (EO) and epichlorohydrin (ECH) using tetraoctylammonium bromide as an initiator and triisobutylaluminum (i-Bu3Al) as an activator wa...The monomer-activated anionic ring-opening copolymerization (AROP) of ethylene oxide (EO) and epichlorohydrin (ECH) using tetraoctylammonium bromide as an initiator and triisobutylaluminum (i-Bu3Al) as an activator was studied. The properties of the copolymers as well as the microstructure have been analyzed in detail via an in situ NMR kinetics study. The statistical copolymers exhibited molecular weights ranging from 2350 g·mol^-1 to 38000 g·mol^-1 (measured by SEC, PEG-standards) and moderate dispersities of 1.27-1.44. The thermal property tests revealed both a glass transition and melting for all copolymers, supporting a block-like nature. Applying in situ NMR kinetic measurements, the reactivity ratios of EO and ECH were determined to be strongly disparate, i.e., rEo = 9.2 and rECH = 0.10. This shows that the simple one-pot statistical anionic copolymerization of EO and ECH via the monomer-activated AROP resulted in the formation of strongly tapered, block-like structures. Furthermore, post-polymerization functionalization of the reactive chloromethyl groups by nucleophilic displacement was investigated for the copolymers. Copolymerization of EO and ECH offers a broad platform for further functionalization and therefore the possibility to prepare a variety of multifunctional PEGs.展开更多
基金Project supported by the National Natural Science Foundation of China.
文摘The block coordination copolymerization of isoprene （Ip） with epichlorohydrin （ECH）has not been reported yet. Deore once studied the anionic type copolymerization ofdiene with ethylene oxide by naphthalene-potassium catalyst and obtained the solid polymerelectrolytes. Based on the coordination polymerization of Ip and ring-openingpolymerization of alkene oxide by rare earth catalysts, we first studied the blockcopolymerization of Ip and ECH in the presence of rare earth coordination catalysts:RE(P<sub>204</sub>)<sub>3</sub>-Al （i-Bu）<sub>3</sub>-halide. The block copolymer which has high molecular weight with
文摘The monomer-activated anionic ring-opening copolymerization (AROP) of ethylene oxide (EO) and epichlorohydrin (ECH) using tetraoctylammonium bromide as an initiator and triisobutylaluminum (i-Bu3Al) as an activator was studied. The properties of the copolymers as well as the microstructure have been analyzed in detail via an in situ NMR kinetics study. The statistical copolymers exhibited molecular weights ranging from 2350 g·mol^-1 to 38000 g·mol^-1 (measured by SEC, PEG-standards) and moderate dispersities of 1.27-1.44. The thermal property tests revealed both a glass transition and melting for all copolymers, supporting a block-like nature. Applying in situ NMR kinetic measurements, the reactivity ratios of EO and ECH were determined to be strongly disparate, i.e., rEo = 9.2 and rECH = 0.10. This shows that the simple one-pot statistical anionic copolymerization of EO and ECH via the monomer-activated AROP resulted in the formation of strongly tapered, block-like structures. Furthermore, post-polymerization functionalization of the reactive chloromethyl groups by nucleophilic displacement was investigated for the copolymers. Copolymerization of EO and ECH offers a broad platform for further functionalization and therefore the possibility to prepare a variety of multifunctional PEGs.
