Synthesis and Microstructurral Study of Stereoblock Elastomeric Polypropylenes from Metallocene Catalyst (2-PhInd)2ZrCl2 Activated with Cocatalyst Mixtures

نویسنده:
, , , , , , ,
سال
: 2013
چکیده: Various elastomeric polypropylenes (PPs) are synthe-

sized through homogeneous propylene polymerization with met-

allocene catalyst (2-PhInd)2ZrCl2 in the presence of different

cocatalyst mixtures: triethylaluminum (TEA)/methylaluminoxane

(MAO) or triisobutylaluminum (TIBA)/MAO in the range of AlAlR3/

AlMAO ¼ 0.0–0.9. The cocatalyst formulation impacts the resultant

polymer microstructure and the thermal and dynamic mechanical

properties of the produced PPs.

13

C NMR analysis of the polymers

reveals essentially atactic PP, with mmmm ¼ 7.9%, when AlAlR3/

AlMAO ¼ 0.0. The mmmm pentad content is maximized when

AlAlR3/AlMAO ¼ 0.8; for TIBA, mmmm ¼ 23.5%; and for TEA,

mmmm ¼ 17.6%. Differential scanning calorimetry analysis and

dynamic mechanical thermal analysis corroborate these findings.

Specifically, Tm, DHm,and Tg are essentially maximized under

these conditions, and the minimum damping is observed for

AlAlR3/AlMAO ¼ 0.6–0.8.

1

H NMR analysis of themixtures of catalyst

and cocatalysts (without monomer) shows very minor differences

for [Zr]:AlAlR3 in the range of 1:1–1:5.V C 2012Wiley Periodicals, Inc.

J. Polym. Sci., Part A: Polym. Chem. 2013, 51,724–731
کلیدواژه(گان): catalysts,elastomers,metallocene catalysts,polyolefins,poly(propylene) (PP)
کالکشن :
  • نمایش متادیتا
  • آمار بازدید