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通过反相微乳法和共沉淀法合成了钴锌双金属氰化物催化剂。研究了制备方式及共聚反应条件对其催化性能及聚碳酸酯组成的影响。结果表明,反相微乳法制备的DMCC-1具有较低的结晶度且可以配合更多的有机配体,在80℃、4 MPa条件下,采用一步加料法催化CO2与环氧丙烷共聚,所制备的聚碳酸酯中碳酸酯单元量达43.5%,数均分子量达36 400,且聚合物分散指数仅为2.07。共聚结果表明,一步加料法有利于提高聚合物的数均分子量,而逐步加料法有利于降低聚合物的相对分子量分布。
Cobalt-zinc double metal cyanide catalysts were synthesized by reverse microemulsion method and coprecipitation method. The effects of preparation methods and copolymerization conditions on the catalytic performance and the composition of polycarbonates were investigated. The results showed that DMCC-1 prepared by reverse microemulsion method has a low degree of crystallinity and can be used with more organic ligands to catalyze the copolymerization of CO2 and propylene oxide by one-step feeding at 80 ℃ and 4 MPa. The amount of carbonate units in the prepared polycarbonate was 43.5%, the number average molecular weight was 36 400, and the polymer dispersion index was only 2.07. The copolymerization results show that the one-step feeding method is beneficial to increase the number average molecular weight of the polymer, and the stepwise feeding method is beneficial to reduce the relative molecular weight distribution of the polymer.