文献类型：期刊文献

英文题名：Polymerization of Methyl Methacrylate with α-Diimine Nickel (II)

作者：Zhang Danfeng[1];Li Sen[1];Yu Wen[1];Meng Jiangang[1]

机构：[1]E China Univ Sci & Technol, Sch Mat Sci & Engn, Shanghai Key Lab Adv Polymer Mat, Shanghai 200237, Peoples R China

年份：2014

卷号：35

期号：7

起止页码：1559

外文期刊名：CHEMICAL JOURNAL OF CHINESE UNIVERSITIES-CHINESE

收录：;EI(收录号：20143218028491);WOS:【SCI-EXPANDED(收录号:WOS:000339471200030)】；

语种：英文

外文关键词：Late transition metal catalyst; alpha-Diimine nickel complex; Methyl methacrylate; Polymerization

摘要：Four alpha-diimine nickel (II) complexes: [(t-Bu)-N = CH-CH =N-(t-Bu)]NiBr2 (C1), [C6H5-N = C(Me-C(Me) = N-C6H5]NiBr2 (C2), [(2,6-C6H3(Me))-N = C(Me)C center dot (Me) = N-(2,6-C6H3(Me)(2))]NiBr2(C3) and [(2,6-C6H3 (i-Pr)(2))-N = C(An)-C(An) = N-(2,6-C6H3 (i-Pr)(2)]NiBr2 (An = acenaphthyl) (C4), in the presence of methylaluminoxane(MAO) as cocatalyst, were applied in the polymerization of methyl mathacrylate(MMA). The influence of polymerization parameters, such as molar ratio of Al/Ni, monomer concentration, polymerization temperature and time, as well solvents were studied with complex C2/MAO system. Based on these results, all nickel complexes were compared under optimized polymerization conditions {1. 6 mu mol catalyst, n(Al)/n (Ni) = 800, [MMA] = 2. 9 mol/L, toluene as solvent, 60 degrees C for 4 h}. In each case, syndiotactic enriched polymer was obtained. The complexes with more bulky frame work exhibit lower catalytic activities, for example, C1 with the smallest bulky frame work gives the highest activity, 107. 8 kg/(mol Ni . h) while C4 with the biggest bulky frame work gives the lowest activity, 7. 8 kg/(mol Ni . h); The complexes with more electronic donor substituents exhibit higher activities and molecular weight of PMMA. The activity of C2 is 62. 5 kg/(mol Ni . h), and the molecular weight of PMMA is 5. 0 x 10(4), while that of C3 is 96. 9 kg/(mol Ni . h) and produce higher molecular weight of PMMA (7. 6x10(4)).