New Insights into Crystallization of Heterophasic Isotactic Polypropylene by Fast Scanning Chip Calorimetry

Extensional-flow-induced crystallization of isotactic polypropylene

A filament stretching extensional rheometer with a custom-built oven was used to investigate the effect of uniaxial flow on the crystallization of polypropylene. Prior to stretching, samples were heated to a temperature well above the melt temperature to erase their thermal and mechanical histories and the Janeschitz-Kriegl protocol was applied. The samples were stretched at extension rates in ...

High-pressure crystallization of isotactic polypropylene droplets

Dispersions of isotactic polypropylene (PP) particles in polystyrene (PS) were produced by interfacially driven breakup of nanolayers in multilayered systems that were fabricated by means of layer-multiplying coextrusion. The droplet size was controlled by the individual PP layer thickness ranging from 12 to 200 nm. In addition, PP was melt blended with PS to produce PP droplets larger than tho...

The role of nucleating agents in high-pressure-induced gamma crystallization in isotactic polypropylene

Nucleation of the γ-form in isotactic polypropylene (PP) under high pressure was investigated. Three nucleating agents were used to nucleate crystallization of PP under atmospheric pressure: commercial Hyperform HPN-20E from Milliken Chemical, poly(tetrafluoroethylene) particles nucleating the α-form, and calcium pimelate nucleating the β-form. Crystallization of neat PP and PP with addition of...

Influence of the temperature on flow-induced crystallization of isotactic polypropylene and propylene-ethylene random copolymer

BOITOUT, Hugo, "Influence of the temperature on flow-induced crystallization of isotactic polypropylene and propylene-ethylene random copolymer" (2014). Influence of the temperature on flow-induced crystallization of isotactic polypropylene and propylene-ethylene random copolymer Influence of the temperature on flow-induced crystallization of isotactic polypropylene and propylene-ethylene rando...

Controlled Crystallization of Isotactic Polypropylene Based on ┙/┚ Compounded Nucleating Agents: From Theory to Practice