| Abstract
| - Ethylene (E)/propylene (P) solution copolymerizations with low propylene ratios were carriedout using constrained geometry catalyst, [C5Me4(SiMe2NtBu)]TiMe2 (CGC), and ansa-zirconocene, rac-Et(Ind)2ZrCl2 (EBI), at 130−150 °C and 3.45 × 103 kPa. Ethylene/propylene copolymers with long chainbranch (LCB) densities from 0.30 to 0.96 carbons per 10 000 carbons, molecular weight distributionsclose to 2, and narrow comonomer composition distributions were synthesized with CGC. Broad molecularweight and comonomer composition distributions were found in the EBI copolymers. Reactivity ratiosshowed that CGC was more active for propylene incorporation than EBI. Terminal group analysis indicatedthat more terminal unsaturation occurred with EBI than with CGC. Two additional types of terminalunsaturated groups, vinylidene with side group having more than three carbons (2VD) and trans-vinylene(VE), were found with EBI while the terminal vinyl (V) and vinylidene with methyl side group (1VD)were determined in both CGC and EBI copolymers. Long chain branch structures were formed by the Vtype macromonomer incorporation. The long chain branching rate constants were also estimated.
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