Toughening Mechanism and Mechanical Properties Simulation of Rubber-Toughened Polymers

Abstract

When blending rubbers into polymers, different rubber distribution status and fraction due to different mechanical property. In this research, effective mechanical properties of rubber-toughened polymers with four blending fraction in six kinds of particle distribution status are simulated numerically by using finite element method. Rubber particle distribution model include four 2D models and two 3D models. Typical effective mechanical properties such as yield stress, Young's modulus, Poisson's ratio and stress-strain curve of each status are obtained. The Results show that all models Young's modulus and Poisson's ratio decrease with rubber particle volume fraction increasing. Young's modulus and Poisson's ratio of three-dimensional body-centered cubic and face-centered cubic models are in a close magnitude range, it means rubber particle volume fraction has less effect on 2D models and two 3D models. As we all known, Matrix yielding, crazing and interface debond. All play an important role in the toughening process of rubber-toughened polymers. So in this paper we also study on toughening mechanism using same models. Our simulation takes use of stress concentration factor, yield ratio and interface elements' strain difference which is related with matrix yielding, crazing and interface debond to study the toughening mechanism. Simulation shows that the maximum stress concentration factor increases with particle volume fraction. The shear yielding occurs first at the equator of rubber particle, and then yield region expands from the equator to the pole of the particle with loads increasing.