THE ATTEMPTED COPOLYMERIZATION OF STYRENE AND ETHYLENE WITH MONOCYCLOPENTADIENYLTITANIUM TRICHLORIDE METHYLALUMINOXANE CATALYST - EFFECT OFPOLYMERIZATION CONDITIONS

The copolymerization of styrene and ethylene was attempted in the pres ence of the catalytic system CpTiCl3-methylaluminoxane. Polymerization s were carried out at different polymerization temperatures and Al/Ti mole ratios. The structure of the polymer was investigated with FTIR, DSC, GPC, and C-13-NMR techniques. The polymerization product ws compo sed of polyethylene and syndiotactic polystyrene. No ethylene-styrene copolymer was detected. The composition of the product was dependent o n the polymerization conditions. The catalyst activity was highest at polymerization temperature 30 degrees C and Al/Ti ratio 1500. Styrene concentration of the product was highest at polymerization temperature 50 degrees C and Al/Ti ratio 1500. The melting temperature of the pol yethylene fraction ws dependent on the styrene content of the product, suggesting some interaction between the monomers in the polymerizatio n reaction. The formation of separate polymer fractions may indicate a different polymerization mechanism for the two monomers, or the prese nce of more than one active species in the catalyst, one producing pol yethylene and the other syndiotactic polystyrene.