IMMOBILIZED CATALYST SYSTEM IN HYDROGENATED HYDROXYLATED POLYBUTADIENE FOR ETHYLENE POLYMERIZATION

This paper is concerned with preparation and use of catalyst systems based on transition metals immobilized on polymeric carriers. Recently, much attention has been given to a new type of support based mainly on the use of polymers and copolymers having pendant or terminal functional groups in the carbon chain. This immobilization is supposed to produce the stabilization of the transition metal valent state. Several methods have been suggested to immobilize transition metal compounds on polymer supports. Among them, the fixation of the transition metal through a chemical interaction with the functional group of the support has been reported. Based on this, the authors have prepared catalyst systems using triisobutyl-aluminum-titanium tetrachloride immobilized on a low-molecular-weight polymer, having pendant or terminal hydroxyl groups as well as double bonds in main chain. The polymerization of ethylene was carried out in a 1-L reactor in hexane at 40 degree C and 100 torr of ethylene pressure for 1 h. The catalyst system was prepared in situ, using the immobilized catalyst and triisobutylaluminum, at 40 degree C under ethylene atmosphere. The polymer was characterized by IR spectrometry and viscometry.