Micro-to Mesoscopic Deformation Behavior of Spherulite of Semi-Crystalline Polymer

Abstract

In the present study, we clarify the micro- to mesoscopic deformation behavior of semi-crystalline polymer by employing large-deformation finite element homogenization method. 3D structure of lamellae in the spherulite of high density polyethylene is modeled, and tensile/compressive deformation behavior was investigated. A series of computational simulation clarified the difference in degree of strain hardening of tension and compression due to different directional orientation hardening. The localized deformation appears depending on the initial distribution of lamellar direction and interaction with surroundings in the mesoscopic area. These mesoscopic deformations are closely related to such microscopic deformation behavior as the rotation of molecular chains which is characterized by the stretch direction and principal slip system in the crystalline phase. Furthermore, interlamellar shear and normal strain in the amorphous phase generally depend on the direction of initial lamellar normal, however, marked scattering is observed due to the interaction with surroundings.