SYNDIOSPECIFIC POLYMERIZATION OF STYRENE OVER SILICA-SUPPORTED CPTICL(3) CATALYSTS

An homogeneous CpTiCl(3) catalyst and two types of silica-supported Cp TiCl(3) catalysts (CpTiCl(3)/SiO2 and CpTiCl(3)/MAO/SiO2) were used to investigate the catalytic behavior for styrene polymerization. Among these, the CpTiCl(3)/SiO2 catalyst showed the highest catalytic activi ty and syndiotacticity in styrene polymerization. From an electron spi n resonance (ESR) study, it is suggested that the CpTiCl(3)/SiO2 catal yst is easily activated for styrene polymerization through interaction with MAO as a cocatalyst. The intensities of ESR signals with g value s of 1.984 and 1.980 were found to be well correlated with polymerizat ion activity. The CpTiCl(3)/SiO2 catalyst was more stable than the hom ogeneous CpTiCl(3) catalyst. Copyright (C) 1996 Elsevier Science Ltd