Iran Polymer and Petrochemical Institute Polyolefins Journal 2322-2212 2 1 2015 01 01 Active site nature of magnesium dichloride-supported titanocene catalysts in olefin polymerization 57 63 1114 10.22063/poj.2015.1114 EN Toshiaki Taniike School of Materials Science, Japan Advanced Institute of Science and Technology, 1-1 Asahidai, Nomi, Ishikawa 923-1292, Japan Keisuke Goto School of Materials Science, Japan Advanced Institute of Science and Technology, 1-1 Asahidai, Nomi, Ishikawa 923-1292, Japan Minoru Terano School of Materials Science, Japan Advanced Institute of Science and Technology, 1-1 Asahidai, Nomi, Ishikawa 923-1292, Japan Journal Article 2014 11 17 Heterogeneous Ziegler-Natta and homogeneous metallocene catalysts exhibit greatly different active site<br />nature in olefin polymerization. In our previous study, it was reported that MgCl2-supported titanocene<br />catalysts can generate both Ziegler-Natta-type and metallocene-type active sites according to the type of activators.The dual active site nature of the supported titanocene catalysts was further explored in the present study: The influence of the ligand structure of titanocene precursors was studied on the nature of active sites when supported on MgCl2 in ethylene and propylene homopolymerization, and ethylene/1-hexene copolymerization. It was found that the reducibility of titanocene precursors by alkylaluminum is closely related to the appearance of the dual active site nature, while the kind of olefin did not affect the type of active sites formed during polymerization. The Ziegler-Natta-type active sites produced poorly isotactic polypropylene and less branched polyethylene, while the metallocene-type active sites produced atactic polypropylene and exhibited much higher incorporation efficiency for 1-hexene. http://poj.ippi.ac.ir/article_1114_8babadc8ab720401083d91a682318328.pdf