硼氢化稀土-二乙基锌-甘油三元体系催化环氧丙烷与CO_2共聚反应

Copolymerization of Propylene Oxide and CO_2 Catalyzed by a Rare Earth Borohydride-Diethylzinc-Glycerine Ternary System

由硼氢化稀土、二乙基锌和甘油制备了三元体系Ln(BH4)3·3THF-ZnEt2-Gly(甘油)用于催化环氧丙烷(PO)与CO2共聚反应,详细考察了催化剂组成、不同稀土元素和溶剂性质对聚合反应的影响.通过正交试验优化的催化剂组成和聚合条件为:Y(BH4)3·3THF-ZnEt2-Gly(摩尔比=3:60:20)催化剂,乙二醇二甲醚溶剂,PO/Y摩尔比1000,[Y]=6.67mmol/L,p(CO2)=3.0MPa,80°C,6h.最高催化效率可达4908g/(mol?h);碳酸酯含量为95.7%,数均分子量为6.97×104.

A ternary catalytic system composed of rare earth borohydrides, diethylzinc, and glycerine has been developed and found to be effective for the copolymerization of propylene oxide （PO） with carbon dioxide. The effect of catalyst composition and reaction conditions on the copolymerization was examined through orthogonal experiments. With Y（BH4）3·3THF-ZnEt2-glycerine molar ratio of 3：60：20, the highest turnover frequency （TOF） of 4 908 g/（mol？h） was achieved at 80 °C and 3.0 MPa of CO2 using 1,2-dimethoxyethane as solvent. The poly（propylene carbonate） had a carbonate unit content of 95.7% and number-average molecular mass of 6.97 × 104.