文献类型：期刊文献

英文题名：A catalytic system including Al(OiPr)3 as a promoter for atom transfer radical polymerization

作者：Guo, JH; Luo, XN; Wu, PP; Han, ZW

机构：[1]E China Univ Sci & Technol, Dept Polymer Sci & Engn, Shanghai 200237, Peoples R China

年份：1999

期号：6

起止页码：725

外文期刊名：ACTA POLYMERICA SINICA

收录：;WOS:【SCI-EXPANDED(收录号:WOS:000084643000014)】；

语种：英文

外文关键词：atom transfer radical polymerization; "living" radical polymerization; n-butyl methacrylate; aluminum triisopropoxide

摘要：Atom transfer radical polymerization (ATRP) of n-butyl methacrylates (BMA) has been achieved with ethyl 2-bromoisobutyrate [(CH3)(2)CBrCO2C2H5] as an initiator and CuBr, 2, 2'-bipyridine(bpy) and aluminum triisopropoxide [Al(OiPr)(3)] as a ternary catalyst system in cyclohexanone. The kinetics and mechanism of polymerization were discussed in detail. Al(OiPr)(3), a bulky Lewis acid, which is used as a catalytic promoter, may coordinate the ester carbonyl of the initiator and polymer and activate the carbon-bromine bond. Therefore, BMA can be polymerized at a lower temperature. The influence of Al(OiPr)(3) on polymerization rate and molecular weight distributions were also studied. The polymerization of BMA became slower and more controlled with CuBr2 than without CuBr2. In the absence of CuBr2, the polymerization of BMA were the rapider and less controlled at 28 degrees C. In the presence of CuBr2, the polymers produced at 52 degrees C had narrow molecular weight distributions (MWD = 1.2 similar to 1.5) and designed molecular weights which were nearly proportional to monomer conversion. The logarithmic conversion data plotted against time (ln([M](0)/[M]) versus time) followed a current first order kinetics.