Elastomeric Poly(propylene): Propagation Models and Relationship to Catalyst Structure

Thermal Behavior, Structure and Morphology of Propene/Higher 1-Olefin Copolymers

“…Similar equations were reported in the literature [29,45,46] to calculate n iso values for propene homopolymers when only the isolated stereoerrors, typical of enantiomorphic site mechanism, interrupt the isotactic sequences. Apart from the two propene homopolymers, which present longer average isotactic sequences, the n iso values of the copolymers with comparable amounts of comonomer fall in a relatively narrow range.…”

Synthesis and properties of elastomeric poly(propylene)

“…The mmmm pentad content of the prepared polymers varies from 8 up to 22%, whereas the mmmr content does not change significantly, having a value of approximately 14%. Consequently, the average length of isotactic sequences, n iso , which can be calculated according to the formula n iso = 4 + 2([mmmm]/ [mmmr]) 13) , increases with increasing isotactic content. Thus, for the three polymers in Fig.…”

Propylene Polymerization Catalyzed by rac-Et(Ind)2ZrCl2/Cp2ZrCl2 in the Presence of ZnEt2

“…Therefore, isotactic-atactic stereoblock polypropylenes have been widely used as adhesives, sealants and coatings, additives for building top grade high way and so on [1,2]. Isotactic-atactic stereoblock polypropylenes are typically synthesized by the asymmetric homogeneous metallocene catalysts, such as rac-Et[(Me 4 -Cp](Ind)TiCl 2 , Me 2 Si[(Me-Ind)(Ind)]ZrCl 2 , rac-[Et(Flu)(2-Me-Flu)]ZrCl 2 and rac-[Et(Flu)(2-Me-benInd)]ZrCl 2 [3][4][5][6]. However, the microstructure and property of block polypropylenes heavily depends on structure of catalysts symmetry, co-catalyst employed and polymerization condi-tions [7,8].…”