Magnesium chloride supported high mileage catalysts for olefin (decene‐l) polymerization XIV. Propagation and chain transfer

Abstract

AbstractDecene‐l was polymerized with the MgCl2/ethylebenzoate/p‐cresol/AIEt3/TiCl4‐AlEt3/methyl‐p‐toluate catalyst at 50° using an A/T ratio of 167 and a range of monomer concentration. The concentration of the two kinds of active sites are [Ti] = 12% and [Ti] = 4% of the total titanium. The rate constants of propagation are 24 M−1 s−1. Chain transfers to AIEt3, monomer, and by β‐hydride elimination have rate constant values of 1.7 × 10−3 M−1 s−1, 1.34 × 10−2 M−1 s−1, and 1.7 × 10−2 s−1, respectively. Poly(decene‐l) have relatively narrow MW which are unchanged during the course of a polymerization. Therefore, the active site concentrations in the CW catalyst for propylene and decene polymerization are identical and their rate constant values agree within a factor of 2. However, the rate of decene polymerization depends on fractional order of monomer concentration and decreases with the increase of activator concentration. Furthermore, the formation of metal polymer bonds has a rate independent of these concentrations. These kinetic behaviors are a manifestation of absorption processes of these species which are not seen in propylene polymerizations.