Dienes effects on terpolymerization of ethylene propylene and diene with ethylenebis (indenyl) zirconium dichloride/methylaluminoxane catalyst

Abstract

Copolymerization of ethylene (E) and propylene (P) with and without diene addition were performed using rac-ethylenebis(indenyl)zirconium dichloride (Et[Ind][subscript 2]ZrCl[subscript 2]) catalyst system in the presence of methylaluminoxane (MAO) as a cocatalyst. Batch and semibatch reactor system were used. The different types of diene i.e. 1,4 HD, 1,5 HD, ENB, VCH and COD were chosen. A small amount of dienes added could have impact on behaviors of ethylenepropylene (EP) copolymerization. In the batch reactor system, the addition of dienes resulted in a slight decrease in polymerization activities. Furthermore, the types of diene did not exhibit any differences in activity. The addition of dienes can alter the incorporation of ethylene and propylene in the polymer backbone according to different types of diene used. The dienes (except for ENB) did not incorporate in the polymer backbone pronouncedly. In addition the melting temperature of EP elastomers increased with the addition of dienes. For the semibatch reactor system, the activities decreased with diene addition in all E/P ratio. However, the activities increased with decreasing the E/P ratio. It was found that only ENB, 1,4 HD and 1,5 HD can incorporate in the polymer backbone. The melting temperature of EP elastomers tended to increase with the addition of dienes. In addition, the thermal properties are also dependent on the fraction of ethylene and propylene in the polymer backbone. It was concluded that the addition of only a small amount of dienes could alter the behaviors of EP copolymerization. In particular, changes in polymerization behaviors were dependent on E/P ratios and types of diene