Multiscale modeling of particle-modified semicrystalline polymers

Abstract

An effective procedure for toughening semicry stalline polymeric materials is to blend them with second-phase rubber particles. A micromechanically developed numerical model for the elasto-plastic deformation and texture evolution of semicrystalline polymers is developed and used to simulate the behavior of particle-modified polyethylene. The constitutive properties of the material are characterized at the microscopic scale where the individual crystallographic lamellae and amorphous layers can be identified. A multiscale numerical model is used to investigate the effect of a specific microstructural morphology on the mechanical behavior of particle-dispersed systems. A polycrystalline model is used for the polymer matrix material. The basic structural element in this model is a layered two-phase composite inclusion, comprising both a crystalline and an amorphous domain. The averaged fields of an aggregate of composite inclusions, which have either random or preferential orientations, form the constitutive response of a polymeric matrix material. Transcrystallized orientations are found to have a limited effect on matrix shear yielding and alter the triaxial stress field.