Dynamic behavior and flame retardancy of HDPE/hemp short fiber composites: Effect of coupling agent and fiber loading

This work aimed at investigating the effect of maleic anhydride-grafted polyethylene (MAPE) as coupling agent and of hemp fiber loading on the compressive dynamic behavior and flammability of high-density polyethylene (HDPE)/hemp short fiber composites. The compressive modulus, the yield stress increased with the presence of MAPE and with the loading of hemp fiber. However, the absorbed energy increased with the presence of MAPE and with the loading of hemp fiber up to 15 wt.%. Halpin–Tsai and Pukánszky models were successfully used to predict the compressive modulus and the yield stress of the composites, respectively. Cone calorimeter measurements showed that the peak of heat release rate (pHRR) was lowered in the presence of MAPE and hemp fiber in comparison to neat HDPE and that this decrease was higher when the fiber content increased. The compatibilization between hemp fiber and HDPE via MAPE was suitable to improve the dynamic behavior and flame retardancy of the composite.