氧化锌催化丁二酸二甲酯和碳酸乙烯酯的耦合反应

研究了ZnO催化碳酸乙烯酯和丁二酸二甲酯耦合反应合成聚丁二酸乙二醇酯预聚体和碳酸二甲酯的新工艺。考察了ZnO催化剂焙烧温度对耦合反应的催化活性,优化了反应条件。并对ZnO催化剂进行XRD、BET和NH₃-TPD表征。以FTIR和¹H NMR表征聚丁二酸乙二醇酯预聚体。结果表明,在225~235℃,EC/DMSu摩尔比为2,催化剂/(EC+DMSu)摩尔比为0.005,反应时间为3 h的反应条件下,碳酸二甲酯收率为59.7%,聚丁二酸乙二醇酯预聚物的特性黏度为0.3857 dl·g^-1。通过XRD和NH₃-TPD分析,推测ZnO表面的晶体缺陷和弱酸性是影响耦合反应催化活性的原因。

Coupling reaction of dimethyl succinate and ethylene carbonate over zinc oxide

A new technology of synthesis of poly(ethylene glycol succinate)(PES)oligomers and dimethyl carbonate(DMC)by coupling reaction of ethylene carbonate(EC)and dimethyl succinate(DMSu)over ZnO was studied.The effect of calcination temperature of ZnO catalysts on catalytic activity was investigated and ZnO catalysts were characterized with XRD,BET and NH₃-TPD.PES oligomers were characterized with FTIR and ¹H NMR.The preferable reaction conditions were as follows:reaction temperature 225-235℃,molar ratio of EC to DMSu 2,molar ratio of catalyst to the total mass of EC and DMSu 0.005,reaction time 3 h.Under these conditions,the yield of DMC was 59.7%,the intrinsic viscosity of PES oligomer was 0.3857dl·g^-1.The catalytic activity of coupling reaction was affected possibly by the degree of crystallization and the weak acid sites on the surface of ZnO.