Cp′Ti(OAr)Cl2/[Ph3C]^+[B(C6F5)4]^-催化体系合成高相对分子质量无规聚丙烯弹性体

Synthesis of High Molecular Weight Atactic Polypropylene Elastomer by Catalytic System of Cp′Ti(OAr)Cl2/[Ph3C]^+[B(C6F5)4]^-

以相应的Cp′TiCl3为原料(Cp′为取代环戊二烯基)制备了3种非桥联单茂金属催化剂1,2,3,4,5-五甲基-环戊二烯基-2,4,6-三叔丁基酚氧基二氯化钛(A)、1-苯基-2,3,4,5-四甲基-环戊二烯基-2,4,6-三叔丁基酚氧基二氯化钛(B)和1,2-二苯基-4-甲基-环戊二烯基-2,4,6-三叔丁基酚氧基二氯化钛(C)。研究了铝钛摩尔比(n(Al)/n(Ti))和温度(T)对催化剂的活性及聚合物相对分子质量(Mw)的影响。结果显示,应用Al(^iBu)3-[Ph3C]^+[B(C6F5)4]^-助催化剂,在合适的Al/Ti(摩尔比160)和温度(70℃)下,3种配合物催化丙烯聚合均具有良好的催化活性(5.15×10^6~6.12×10^6 gPP/(mol Ti·h)),可以制备出高相对分子质量(Mw=8.54×10^4~29.26×10^4)无规聚丙烯弹性体。

Three non-bridged titanium(IV)cyclopentadienyl-aryloxy complexes such as 1,2,3,4,5-pentamethyl-cyclopentadienyl-2,4,6-tri-tert-butylphenoxytitanium(IV)dichloride(A),1-phenyl-2,3,4,5-tetramethyl-cyclopentadienyl-2,4,6-tri-tert-butylphenoxytitanium(IV)dichloride(B)and 1,2-diphenyl-4-methyl-cyclopentadienyl-2,4,6-tri-tert-butylphenoxytitanium(IV)dichloride(C)could be prepared from corresponding Cp′TiCl3(Cp′=cyclopentadienyl).The influence of the mole ratio of Al/Ti(n(Al)/n(Ti))and temperature(T)on the catalytic activity and the polymer molecular weight(Mw)was investigated.The results show that when activated by Al(^iBu)3-[Ph3C]^+[B(C6F5)4]^-cocatalyst,three complexes show higher catalytic activities for the propylene polymerization(5.15×10^6~6.12×10^6 g PP/(mol Ti·h))and the atactic polypropylene elastomers with high molecular weight(Mw=8.54×10^4~29.26×10^4)could be produced through propylene polymerization at the suitable mole ratio of Al/Ti(160)and temperature(70℃).