Kinetics of oriented crystallization of polymers in the linear stress-orientation range in the series expansion approach

An analytical formula is derived for the oriented crystallization coefficient governing kinetics of oriented crystallization under uniaxial amorphous orientation in the entire temperature range. A series expansion approach is applied to the free energy of crystallization in the Hoffman-Lauritzen kin...

Full description

Saved in:
Bibliographic Details
Main Authors: L. Jarecki, R. B. Pecherski
Format: Article
Language:English
Published: Budapest University of Technology and Economics 2018-04-01
Series:eXPRESS Polymer Letters
Subjects:
Online Access:http://www.expresspolymlett.com/letolt.php?file=EPL-0008746&mi=cd
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:An analytical formula is derived for the oriented crystallization coefficient governing kinetics of oriented crystallization under uniaxial amorphous orientation in the entire temperature range. A series expansion approach is applied to the free energy of crystallization in the Hoffman-Lauritzen kinetic model of crystallization at accounting for the entropy of orientation of the amorphous chains. The series expansion coefficients are calculated for systems of Gaussian chains in linear stress-orientation range. Oriented crystallization rate functions are determined basing on the ‘proportional expansion’ approach proposed by Ziabicki in the steady-state limit. Crystallization kinetics controlled by separate predetermined and sporadic primary nucleation is considered, as well as the kinetics involving both nucleation mechanisms potentially present in oriented systems. The involvement of sporadic nucleation in the transformation kinetics is predicted to increase with increasing amorphous orientation. Example computations illustrate the dependence of the calculated functions on temperature and amorphous orientation, as well as qualitative agreement of the calculations with experimental results.
ISSN:1788-618X