SUPPORTED CATALYST WITHOUT EXTERNAL ELECTRON DONOR FOR PROPYLENE POLYMERIZATION Ⅱ. TACTICITY DISTRIBUTION AND MICROSTRUCTURE OF POLYPROPYLENE

• 来源期刊: 高分子科学（英文版）
• 学科: 化学
• 年，卷（期）: 1998,（1）
• 页码范围: 56-61
• 页数: 6页
• 分类号: O6
• 语种: 英文

摘要

Propylene was polymerized with a novel supported Ziegler-Natta catalyst containing 2,2-di-iso-butyl-1,3-dimethoxy-propane (DIBDMP) as internal donor and in the absence of external donor. The tacticity distribution of polypropylene was obtained by using temperature rising elution fractionation (TREF) technique and microstructure of fractions was studied with 13C-NMR. Compared with the catalyst without electron donor, this catalyst gives a considerably narrower tacticity distribution. Fractionation data demonstrate that DIBDMP shows better performance than aromatic diester DNBP (di-n-butyl phthalate). Chemically inverted propylene units and less stereoblockiness are found in the first fraction. Possible reasons for these were presented.