SiO2/MgCl2·xBu(OH)2/poly(styrene-co-acrylic acid) inorganic/organic hybrid support was synthesized and was of three types of chemical environments: inorganic support SiO2

MgCl2·xBu(OH)2  adduct and organic support PSA.TiCl4 was immobilized on the hybrid support.The influences of its composition on the titanium content

catalyst morphology and performance in ethylene polymerizations were also investigated.The results showed that titanium content decreased sharply when PSA was added to the hybrid support.The kinetic study of ethylene/1-hexene copolymerization indicated that there was a long period of diffusion-controlled induction time at the initial stage for the hybrid catalysts

due to the barrier effect from PSA

comparing with SiO2/MgCl2·xBu(OH)2/TiCl4 that had no induction time in ethylene polymerization. As the content of PSA increased

the induction time extended and almost no decay happened until the end of the polymerization.Moreover

the polyethylene produced by SiO2/MgCl2·xBu(OH)2/PSA/TiCl4 was of broader molecular weight distribution(MWD) and high melt flow ratio. Based on its morphological features showed by SEM

the polymerization mechanism of the hybrid catalysts was also investigated.