Studies on the molecular weight dependence of tacticity of anionically prepared PMMAs by on-line GPC/NMR
Studies on the molecular weight dependence of tacticity of anionically prepared PMMAs by on-line GPC/NMR
复制标题
通过在线 GPC/NMR 研究阴离子制备 PMMA 立构规整度的分子量依赖性
DOI：
10.1007/bf00419976
复制
发表时间：
1990
期刊：
影响因子：
3.2
通讯作者：
N. Fujimoto
中科院分区：
文献类型：
--
作者：
K. Hatada;K. Ute;T. Kitayama;T. Nishimura;M. Kashiyama;N. Fujimoto
摘要使用 t-C4H9MgBr、n-C4H9MgCl、1,1-二苯基己基锂、t-C4H9Li 和 t-C4H9Li(n−C4H9)3Al 配合物等阴离子引发剂在甲苯中制备的几个 PMMA 样品，通过在线 GPC/NMR 方法进行分析，使用 500 MHz 1H NMR 光谱仪作为实时分析 GPC检测器。分子方法时间短（每个样品≤60 分钟），样品量小（约 1 mg）。 mm-和rr-三联体引起的α-甲基质子共振强度与洗脱时间的关系图显示了立构规整度随PMMA分子量的变化。根据结果，讨论了聚合反应中活性物质的性质。
SummarySeveral PMMA samples prepared in toluene with anionic initiators such as t-C4H9MgBr, n-C4H9MgCl, 1,1-diphenylhexyllithium, t-C4H9Li and t-C4H9Li(n−C4H9)3Al complex were analyzed by the on-line GPC/NMR method using a 500 MHz 1H NMR spectrometer as a real-time detector of GPC. The molecular method for a short time (≤60 min per sample) with a small amount of the sample (≈1 mg). The plots of intensities of the α-methyl proton resonances due to mm- and rr-triads against elution time showed the variation of tacticity with molecular weight of the PMMA. On the basis of the results, the natures of active species in the polymerizations were discussed.