Propylene Polymerization Performance with Ziegler-Natta Catalysts Combined with U-Donor and T01 Donor as External Donor

Abstract

In propylene (C3) polymerization with Ziegler-Natta catalyst, not only internal donor but also external donor is very important to make isotactic polypropylene (PP) with higher yield. Most propylene-based polymers have been commercially produced with Ziegler-Natta catalysts combined with dialkyl-dialkoxy silane compounds (R2Si(OR)2) such as C-donor, P-donor, and D-donor as external donors. In this paper, we will introduce the propylene polymerization performance with aminosilane compounds, i.e., diethylamino triethoxy silane (U-donor) and bis(ethylamino) di-cyclopentyl silane (T01 donor), as external donor in Ziegler–Natta catalyst. The polymerization screening experiments were conducted using some triethoxyalkylsilanes compounds (1–7) and performances were compared with U-donor. The polymerization results of the binary donor system show improvement in stereoregularity. These aminosilane compounds exhibit high hydrogen response in propylene polymerization and high copolymerization performance of propylene (C3) and ethylene (C2) in ICP production compared with dialkyl-dialkoxy silane compounds. While using methanol as an additive along with external electron donor, as a serendipitous, the copolymerization activity, block ratio, EPR (ethylene-propylene rubber) content improve significantly for U-donor as compared with T01 donor and C-donor.