Effects of comonomer on active center distribution of TCl4/MgCl2–AlEt3 catalyst in ethylene/1-hexene copolymerization

摘要: Abstract Ethylene/1-hexene copolymerization with MgCl2/TiCl4–AlEt3 catalyst has been conducted under different initial 1-hexene concentration (0–0.5 mol/L). Number of polymerization active centers was determined by quenching the reaction 2-thiophenecarbonyl chloride and measuring sulfur content quenched polymer. Each copolymer sample fractionated into boiling n-heptane soluble insoluble fractions, in these fractions were also counted. The rate constants ethylene insertion calculated, respectively. Molecular weight distribution (MWD) curves polymers deconvoluted 4–5 Flory components, changes activity components [1-hexene] analyzed. number significantly enhanced increasing [1-hexene]. Large revived small amount 1-hexene. With increase [1-hexene], producing polymer chains lower molecular higher increased more than those content, MWD curve continuously inclined to low side. incorporation have relatively smaller constant insertion. When increased, only slightly changed, but markedly lowered, meaning that ability incorporating