A Model for Flow-enhanced Nucleation Based on Fibrillar Dormant Precursors

作者：Roozemond Peter C; Steenbakkers Rudi J A; Peters Gerrit W M^*

来源：Macromolecular Theory and Simulations, 2011, 20(2): 93-109.

DOI：10.1002/mats.201000059

• crystallization
• flow-enhanced nucleation
• poly(propylene) (PP)
• simulations
• viscoelastic constitutive models

A model for flow-enhanced nudeation is presented based on the concept of a polymer melt containing a fixed number of nudeation precursors with a fixed size distribution. Depending on the size, precursors can either be active (i.e. susceptible to nudeation, the characteristic time scale of which is governed by the deformation rate) and grow into a spherulite or remain dormant. The size distribution of precursors is derived by combining nucleation theory and experimentally determined quiescent spherulite number densities. Longitudinal precursor growth, causing activation of dormant precursors, is a function of molecular deformation: the stretch of high molecular weight chains. Both the eXtended Pom-Pom and the Rolie-Poly model are tested to calculate the molecular deformation. A quantitative agreement is found between simulations and experimental results.

• 出版日期2011-2-10