کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
69235 | 48534 | 2006 | 6 صفحه PDF | دانلود رایگان |

A study of the effect of “trimethylaluminium (TMA)-depleted” methylaluminoxane (MMAO) and alkylaluminiums on propylene polymerization at high temperature in the use of a TiCl4/MgCl2/aromaticdiester-alkoxysilane catalyst has shown that, MMAO was not the actual cocatalyst. However, at low Et3Al/Ti mole ratio addition of MMAO to catalyst improved the catalyst activity and stereospecificity and the catalyst showed a high proportions of isotactic polypropylene (95%) and high activity with the mixture of MMAO and Et3Al at 100 °C. Addition of MMAO reduced the molecular weights of isotactic polypropylene (iPP) but had no effect on the crystallinity of the iPPs. The appearance of β modification in the iPP obtained with Et3Al crystallization process implied that the microstructure of iPP obtained with Et3Al was different from that of iPP obtained with i-Bu3Al and Hex3Al at 100 °C.
A study of the effect of “trimethylaluminium (TMA)-depleted” methylaluminoxane (MMAO) and alkylaluminiums on propylene polymerization at high temperature in the use of a TiCl4/MgCl2/aromaticdiester-alkoxysilane catalyst has shown that, the catalyst showed a high proportions of isotactic polypropylene (95%) and high activity when the mixture of MMAO and Et3Al was used as cocatalyst at 100 °C. The appearance of β modification in the isotactic polypropylene (iPP) obtained with Et3Al crystallization process implied that the microstructure of iPP obtained with Et3Al was different from that of iPP obtained with i-Bu3Al and Hex3Al at 100 °C. Figure optionsDownload as PowerPoint slide
Journal: Journal of Molecular Catalysis A: Chemical - Volume 243, Issue 2, 16 January 2006, Pages 198–203