Spherulitic Nucleation and Growth Rates in an iPP under Continuous Shear Flow

Abstract

The study of polymer crystallization enhanced by flow has attracted much interest because it implies the possibility of controlling the final morphology and the resulting mechanical and functional properties of semicrystalline polymers. An improved understanding of the fundamentals of flow-enhanced crystallization effects can help to tailor advanced processing strategies. Indeed, a complete understanding of the fundamentals of structure development during processing remains a challenge. In this work, the effect of a steady shear flow applied during crystallization on the morphology evolution and on the kinetics of isothermal crystallization of an iPP has been studied experimentally. In particular, measurements of nucleation and growth rates of spherulites during continuous and constant steady shear flow were performed by means of a Linkam shearing cell coupled with an optical microscope. During all the tests carried out in this work, the dominant crystalline structure was fully spherulitic. It was found t...