Mechanical behavior of interfacial stress transfer in platelet-reinforced thermoset polymeric composites

Abstract

This study models the mechanical performance of thermoset polyamide filled with various percentages of glass beads using a coupling agent. A micromechanical model is developed for polyamide glass-bead composite containing three-phase zones with imperfect bonding across interfaces. The micromechanical/interface model uses square sub-region arrays representing particle, matrix, and interface zones to obtain the stress transfer behavior across the cohesive zone for a given microstructure. Understanding the stress transfer tool and interfacial adhesion across multi-coated inclusions, and developing accurate material models will help in establishing upcoming design criteria in the engineering of polymer based composites. The impact of this study comes from the fact that the diffusion quality and non-uniform distribution of inclusions within the polymer matrix, and weak bonding of filler to the polymer matrix, may result in an ineffective stress transfer, which in turn degrades the mechanical properties of nanocomposites. The influence of incomplete interfacial adhesion on the modulus and strength property of polymer-based composites has been investigated in this study. The coupling agent used had a minor impact on the stiffness of the composite which confirms the fact that stiffness is minimally affected by interfacial bonding. The model also revealed that the maximum obtainable stress decreases with increasing volume fraction of glass present in those composites with no coupling agent.