Effects of polymerization parameters on activity of ethylene/propylene copolymeriation using CP2ZrCl2/MAO catalyst system

Semi-continuous ethylene/propylene copolymerization is carried out at atmospheric pressure in toluene using Cp2ZrCl2/methylaluminoxane catalyst system. The effects of operating conditions including polymerization temperature, monomer feed composition, catalyst/cocatalyst molar ratio and reaction time (as mean residence time of the catalyst system in reactor) on kinetics of the copolymerization is investigated. The catalyst activity seems to increase with a decrease in catalyst concentration but decreasing with either propylene/ethylene molar ratio in feed or with reaction temperature. Chain transfer to propylene is shown to be the main reason for catalyst deactivation. The rate-time profiles are also shown to be of decaying character after passing a maximum indicating that the deactivation of active growing centre occurs as soon as the catalyst components are mixed in the presence of monomer mixture.