US EPA

3859037 

Journal Article 

Effect of aminosilane compounds as external donors on isospecific polymerizations of 1-butene with MgCl2/TiCl4/DIBP catalyst 

Yan, Y; Ren, H; Li, L; Xu, Y 

2017 

Yes 

Catalysis Letters
ISSN: 1011-372X
EISSN: 1572-879X 

147 

1 

221-227 

English 

10.1007/s10562-016-1868-5 

WOS:000394139200024 

Four aminosilane compounds were synthesized and employed as external electron donors for 1-butene polymerization with MgCl2 supported Ziegler-Natta catalyst. The four aminosilane compounds are di(piperidinyl)dimethoxysilane (DPPDMS), di(piperidinyl)- diethoxysilane (DPPDES), di(pyrrolidinyl)dimethoxysilane (DPRDMS) and di(pyrrolidinyl)- diethoxysilane (DPRDES). A detailed study has been performed on the effects of the chemical structure of different external electron donors on the catalytic efficiency, isotacticity, melting temperature and molecular weight distribution of obtained poly(1-butene). Poly(1-butene) products have been characterized with gel permeation chromatography (GPC) and differential scanning calorimetry (DSC) analysis. The results indicated that: first, aminosilane compounds with dimethoxy groups showed higher catalytic efficiency and polymers isospecificity than those of with diethoxy groups. Conversely, the aminosilane compounds with diethoxy groups were conductive to obtaining polymers with broader molecular weight distribution than those of with dimethoxy groups. Second, compared with single DPPDMS or TEOS (tetraethyl orthosilicate), DPPDMS/TEOS complex in a proper molar ratio would not only increase the catalytic efficiency and isotacticity of obtained polymers, but also broaden the molecular weight distribution of polymers. Third, the effects of other factors on catalytic efficiency and isotacticity of polymers product were also studied, including different amount of hydrogen, concentration of external donor and cocatalyst.



Di(piperidinyl)dimethoxysilane (DPPDMS) was synthesized and employed as external electron donors for 1-butene polymerization with MgCl2 supported Ziegler-Natta catalyst. Compared with single DPPDMS or TEOS (tetraethyl orthosilicate), DPPDMS/TEOS complex in a proper molar ratio would not only increase the catalytic efficiency and isotacticity of obtained polymers, but also broaden the molecular weight distribution of polymers. The selection of molar ratio should depend on the requirements to the polymer.



[GRAPHICS] 

Ziegler-Natta catalyst; External donors; Aminosilane compounds; 1-Butene polymerization