Deformation mechanism of polymer spherulite by linear isothermal viscoelastic theory

Abstract

A mathematical representation for the deformation mechanism of polymer spherulite is proposed through a linear isothermal viscoelastic theory to investigate the relaxation mechanism of strains and stresses within the spherulite. This description may be represented by the extension of the method proposed by Chen and Wang concerning an elastic problem. Displacements within the spherulite are obtained as solutions of equations of motion omitting an inertia term by assuming two potential functions of complex quantities. Viscoelastic stiffnesses of lamellae in the equations are obtained by applying the correspondence principle to a composite model, in which the mechanical behavior of amorphous phase and grain boundary region is assumed to be dependent upon a three-element viscoelastic model of Maxwell type. As to the results, both the relaxations of strains and stresses within the spherulite are found to be dependent upon the relaxation of viscoelastic constants in bulk.