Mechanical behavior of high impact polystyrene reinforced with short sisal fibers

In this work the mechanical behavior of high impact polystyrene (HIPS) reinforced with short sisal fibers was investigated. Tensile and fracture tests were performed under quasi-static and impact loading conditions. From uniaxial tensile tests, an increasing trend of Young's modulus with fiber content was found, whereas tensile strength and deformation at break decreased. On the other hand, in fracture tests irrespectively of loading conditions, all materials exhibited non-linear load–displacement curves with stress whitened fracture surfaces. Hence, Non-Linear Elastic Fracture Mechanics was adopted to characterize fracture behavior in these materials. Higher values of quasi-static fracture toughness were exhibited by the composites in comparison to the plain matrix up to a fiber content of about 10 wt% sisal. Conversely, the addition of sisal fibers to the HIPS matrix led to inferior impact fracture properties.