New highly active catalysts Cp * Ti(O-C6H4-X)(3) for bulk syndiospecific polymerization of styrene

作者：Shen, ZG^*; Zhou, WL; Zhu, FM; Lin, SG

来源：Acta Polymerica Sinica, 2004, (1): 45-49.

• ligand
• monotitanocene
• styrene syndiotactic polymerization

Four kinds of ancillary ligands -O-C6H4-X [X(p) = F, Cl, Br, I] were introduced in the design of novel monotitanocene catalysts, Cp * Ti (O-C6H4-X)(3). All of the new catalysts show high activity for styrene syndiotactic polymerization. The catalytic activity of the four monotitanocene increased in the order: Cp* Ti(O-C6H4-I)(3) < Cp* - Ti-(O-C6H4-Br)(3) < Cp* Ti(O-C6H4-Cl)(3) < Cp* Ti(O-C6H4-F)(3). The addition of triisobutylaluminium (TIBA) to the catalyst system caused a dramatic increase of s-PS yield. At 90degreesC, MAO/TIBA/Ti = 400/200/1 ( molar ratio), the catalytic efficiency of Cp* Ti(O-C6H4-F)(3) is up to 3.46 x 10(6) g polymer/mol.Ti.10 min. The polymerization activity of Cp* Ti(O-C6H4-X)(3) at MAO/TIBA/Ti = 400/200/1 (molar ratio) is about 10 times higher than that at MAO/Ti = 600 (in the absence of TIBA). The catalytic efficiency of the catalyst and the molecular weight were affected by catalyst composition, monomer concentration and polymerization temperature. The kinetics of styrene syndiotactic. polymerization in toluene was also studied.

• 出版日期2004-2
• 单位中山大学; 中国石油化工股份有限公司上海石油化工研究院