聚乙烯吡咯烷酮固载卤化锌催化酯交换法合成脂肪族聚碳酸酯  

Synthesis of Aliphatic Polycarbonates by Transesterification Route with Poly(vinylpyrrolidone)-immobilized Zinc Halide as Catalysts

作　　者：王自庆[1,2,3] 杨先贵[1,3] 刘绍英[1,3] 胡静[1] 王公应[1,3] 

机构地区：[1]中国科学院成都有机化学研究所,成都610041 [2]中国科学院大学,北京100049 [3]常州化学研究所,常州213164

出　　处：《高分子学报》2016年第12期1654-1661,共8页Acta Polymerica Sinica

基　　金：十二五国家科技支撑计划(项目号2013BAC11B05);江苏省重点研发计划项目(项目号BE2015055);四川省科技支撑计划项目(项目号2016GZ0228)资助

摘　　要：以聚乙烯吡咯烷酮(PVP)和卤化锌ZnX2(X=Cl、Br和I)反应制备了一系列PVP固载的ZnX2催化剂ZnX2(PVP),用于催化碳酸二苯酯(DPC)和脂肪族二元醇熔融酯交换反应合成高分子量脂肪族聚碳酸酯(APCs).以TGA、FTIR和XPS为表征手段对催化剂结构与性能间的构效关系进行了研究.研究发现,催化剂Lewis酸强度的增强对聚合和分解反应均有明显的促进作用,Zn^(2+)空间位阻的增大则可以降低酯交换反应的剧烈程度,同时还可以有效抑制副反应的进行.与纯ZnBr2相比,ZnBr2(PVP)高温催化性能更优,在最佳工艺条件下合成PBC聚合物的数均分子量Mn可以达到1.59×105,对应收率和PDI值分别为84.5%和1.79.该催化剂的优异性能主要归结于PVP与Zn^(2+)相互作用的存在,可为酯交换反应的进行提供适当Lewis酸性和空间位阻.Poly（vinylpyrrolidone）（PVP） immobilized zinc halides,Zn X2（PVP）（X = Cl,Br and I）,were prepared by reaction of Zn X2 with PVP and used as catalyst for one-pot melt transesterification of diphenyl carbonate（DPC） with diols to synthesize high-molecular-weight aliphatic polycarbonates（APCs）. The relationship of structure and catalytic performance was investigated using elemental analysis,FTIR,TGA and XPS for these catalysts. It was found that Zn^2＋ can be chelated with PVP through two ways,i. e.（a） Zn^2＋ ions anchored to oxygen and nitrogen in one amide moiety;（b） Zn^2＋ ions coordinated to two carbonyl oxygen atoms to from two neighboring amide ligands. The Mw,yield and PDI of obtained PBC were influenced by the halogen anions because the interaction of halogen anions,PVP and Zn^2＋ could obviously affect the varieties of Lewis acidity and steric hindrance of Zn^2＋. Lewis acidity was found to be dominant for the polymerization rate at lower temperature,and increasing steric hindrance seemed to give a positive effect on the improvement of yield. Polymerization and its reverse reaction,decomposition processes,were both promoted by increasing Lewis acidity,and the side reactions would be restrained by increasing the steric hindrance of Zn^2＋. Therefore,the increase of Mwand yield for Zn Br2（PVP） compared with Zn Br2 and Zn Cl2 at a high temperature was mainly resulted from the conflicting factors of Lewis acidity and steric hindrance of Zn^2＋compensated each other,thus generating the best activity for Zn Br2（PVP） at higher temperature,where the highest Mwof 1. 59 ×10^5 with yield of 84. 5% was obtained under suitable reaction conditions. The main reasons for Zn Br2（PVP） catalyst displaying the higher yield and Mwthan other plain zinc halide catalysts should be ascribed to the presence of the interaction between Zn Br2 and PVP,which provided this melt transesterification reaction with appropriate Lewis acidity as well as the steric hindrance. In addition,the elect

关 键 词：卤化锌 聚乙烯吡咯烷酮 脂肪族聚碳酸酯 碳酸二苯酯 熔融酯交换 

分 类 号：TQ323.41[化学工程—合成树脂塑料工业]