A numerical investigation of the potential of rubber and mineral particles for toughening of semicrystalline polymers

The impact strength of many semicrystalline polymers can be improved by the dispersion of second-phase rubber particles. A criterion for the effect of this practice is based on the average interparticle matrix ligament thickness. The critical interparticle distance, below which a substantial toughness increase can be observed, is considered to be an intrinsic material property of the matrix. A toughening mechanism has recently been suggested which considers a layer of transcrystallized material around well-dispersed particles, having a reduced yield strength in certain preferentially oriented directions, thereby opening the possibility of using mineral fillers. In this work, the potential of toughening of semicrystalline polymeric material by local anisotropy in combination with soft rubber and hard mineral filler particles is investigated. The matrix material is modeled within the framework of anisotropic Hill plasticity with a rate dependent and hardening yield stress. Various particle/matrix interface conditions are used to study the role of debonding and cavitation. The presence of debonded moderately stiff or hard fillers is found to affect the shear yielding effect of local anisotropy that was found for voided material. [Copyright &y& Elsevier]