Effect of glass fiber and maleated ethylene-propylene rubber content on the impact fracture parameters of nylon 6

The impact fracture parameters of blends of nylon 6 and maleated ethylene-propylene rubber (EPR-g-MA) reinforced with glass fibres as a function of glass fibre and EPR-G-MA content were examined. Both the linear elastic fracture mechanics (LEFM) model and a modified essential work of fracture (EWF) model were used to analyze the data. It was found that the addition of EPR-G-MA to unreinforced nylon 6 increased the EWF parameters. Beyond a critical rubber content, which coincided with the ductile-to-brittle transition, there was a large increase in these parameters. When glass fibre reinforcement was used without rubber toughening, the EWF model was unable to model the observed fracture response. On the other hand, the LEFM model adequately described the fracture behaviour and it was found that the critical strain energy release rate increased with increasing glass fibre content. (Original abstract - amended)