Thermal behaviour of highly stereoregular syndiotactic polypropene from homogeneous catalysts

Abstract

Abstract Thermal characterization was carried out on highly stereoregular and regioregular syndiotactic polypropene (sPP) obtained with isopropylidene(cyclopentadienyl)(9‐fluorenyl)zirconium dichloride and methylaluminoxane. The influence of molecular weight and syndiotacticity degree on the thermodynamic melting point (T° m ) of sPP were separately investigated by examining samples with a fully syndiotactic pentads content ( rrrr ) ranging from ca. 81% to ca. 94% and with an weight‐average molecular weight (M̄ w ) ranging from 9,6 · 10 4 to 17,3 · 10 4 . Upon excluding any influence of the molecular weight, the correlation between the rrrr pentads content and the T° m of the samples led to the extrapolation of the thermodynamic melting point for a fully syndiotactic polypropene.