Latent bimodal polymerization of 1-hexene by a titanium-based diastereomeric catalyst containing a rac/meso-aminodiol ligand

被引：39

作者：

Manivannan, R ^{[1
]}

Sundararajan, G ^{[1
]}

机构：

[1] Indian Inst Technol, Dept Chem, Madras 600036, Tamil Nadu, India

来源：

MACROMOLECULES | 2002年 / 35卷 / 21期

关键词：

D O I：

10.1021/ma020696b

中图分类号：

O63 [高分子化学（高聚物）];

学科分类号：

070305 ; 080501 ; 081704 ;

摘要：

A New titanium catalyst bearing an aminodiol ligand was synthesized as racemic (C-2), as meso, and as a diastercomeric mixture. The racemic catalyst (rac) produced isotactic polymer by enantiomorphic-site control mechanism whereas meso catalyst (meso) produced atactic oligomers. The rac and the diastercomeric catalyst (mix) produced polymers with single-site catalyst behavior at ambient temperatures. When the polymerization temperature was lowered, rac gave high molecular weight polyhexene with polydispersity value approaching close to a living system whereas the mix exhibited a latent bimodal behavior, meso produced just oligomers and did not show any change in behavior with polymerization temperature. Deliberate mixing of rac and meso produced two polyhexene fractions: high molecular weight polymer and oligomers indicating an independent behavior of the mixed catalyst.

引用

页码：7883 / 7890

页数：8

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