Steric and electronic effects of R in (2-(4-R-C6H4)indenyl)2ZrCl2 catalysts on the synthesis of elastomeric polypropylene
作者:Shirley Lin、Elisabeth Hauptman、Tapan K. Lal、Robert M. Waymouth、Roger W. Quan、Andreas B. Ernst
DOI:10.1016/s1381-1169(98)00006-5
日期:1998.11
Metallocene catalysts derived from bis(2-arylindenyl)zirconium dichloride catalysts yield elastomeric stereoblock polypropylene. A study of the steric and electronic effects of varying the 4-substituent of bis(2-(4-R-C6H4)indenyl)zirconium dichloride [(1 RH, 2 RMe, 3 REt, 4 RnBu, 5 RtBu, 6 RSiMe3, 7 RCF3, 8 RCl)] on propylene polymerization at 25, 50, 75 psig and bulk propylene revealed that
衍生自双(2-芳基茚基)二氯化锆催化剂的茂金属催化剂产生弹性体立体嵌段聚丙烯。的不同之二的4-取代基(2-(4- RC的立体和电子效应的研究6 ħ 4)茚基)二氯化锆[(1个RH,2 RMe,3 REt,4 - [R ñ卜,5 R吨卜,6 RSiMe 3,7 RCF 3,8在25、50、75psig和本体丙烯下的丙烯聚合反应中,这些催化剂的聚合行为不受2-芳基取代基4-位上取代基的性质的强烈影响。的弹性聚丙烯的微观结构的检查出品表明,催化剂2 - 8所述isotacticities变化在小范围内和类似于那些由催化剂产生1(20%≤[MMMM]≤44%)。催化剂的生产率和分子量也显示出相同的趋势。对配合物3进行了晶体学表征,发现其仅以内消旋构象结晶。