Regulation of Stereospecificity of Titanium–Magnesium Catalysts in Propylene Polymerization Reactions
摘要
Abstract
The influence of external donor nature on propylene polymerization reactions with titanium-magnesium catalyst activated with AlEt3 is studied. The use of cyclohexylmethyldimethoxysilane as the donor increases the content of isotactic polymer and the use of 2,6-dimethylpyridine promotes the formation of syndiotactic component in polypropylene. By combining different donors, it is possible to regulate the site distribution in catalytic system with respect to stereospecificity and to modify stereoregularity, molecular weight characteristics and mechanical properties of polypropylene.