Influence of Silane‐Type Electron Donors on Ziegler–Natta Catalysts in Ethylene Polymerization and Ethylene/α‐Olefin Copolymerization

Abstract This study examines the influence of silane‐type electron donors on the performance of Ziegler–Natta (ZN) catalysts in ethylene polymerization and ethylene/α‐olefin copolymerization. Three electron donors, dicyclopentyl dimethoxysilane (D donor), dipiperidyl dimethoxysilane (DPPDMS), and dipyrrolidinyl dimethoxysilane (DPRDMS), were investigated. The presence of electron donors generally reduces catalytic activity in both homo‐ and copolymerization, with aminosilanes (DPPDMS and DPRDMS) causing a more pronounced decrease than D donor due to their stronger coordination with Ti active sites. The addition of electron donors also increases polymer molecular weight while narrowing molecular weight distribution, particularly in ethylene/1‐butene copolymerization. Although comonomer incorporation remains low regardless of donor type, the resulting copolymers exhibit a more uniform chemical composition distribution compared to those synthesized without electron donors. Notably, polymers produced with D donor display a narrower molecular weight distribution than those obtained with aminosilane donors. These findings should provide valuable insights into the role of silane‐type electron donors in tuning copolymer properties and contribute to the advancement of ZN catalysis in copolymerization.