In this article, mechanical and fracture properties of two types of nanoparticles, namely fumed silica (FS) and halloysite nanotube filled polypropylene (PP) toughened with two types of thermoplastic elastomers (TPOs), namely ethylene-based TPO (ETPO) and propylene-based TPO (PTPO) were investigated. A full factorial design was exploited to clarify the influence of each factor as well as its interaction on outcomes. The essential work of fracture (EWF) approach was utilized to study the effect of each factor on fracture behavior. The addition of TPO enhanced the elongation at break and non-EWF by 62% and 40%, in turn. In addition, the tensile strength, modulus, and EWF increased by 8%, 34%, and 7%, respectively, by increasing the nanoparticles up to 1 wt%. The blend nanocomposite with 10 wt% of PTPO and 1 wt% of FS was selected as the best stiffnesstoughness-strength equivalence based on optimization results. Additionally, the R 2 extracted from the analysis of variance (ANOVA) and plots of normal probability indicated good agreement between the experimental data and for foreseen one using full factorial models.

In this research, tensile and fracture behavior of polypropylene (PP) toughened with two types of thermoplastic polyolefin elastomers (TPOs) and filled with fumed silica are investigated. The TPOs are both propylene- and ethylene-based thermoplastic elastomers. Three percentages of TPO (0, 10, and 20 wt%) and four percentages of fumed silica (0, 1, 3, and 5 wt.%) are used. The addition of ethylene-based TPO to PP show higher values of modulus and tensile strength than propylene-based TPO. In contrast, propylene-based TPO show higher elongation at break which by increasing this type of TPO the elongation at break increase by 788%. The presence of fumed silica in the PP/TPOs blend improve the tensile strength and modulus but declined the elongation at break. Fracture behavior analysis of these compounds is performed by utilizing the essential work of fracture (EWF) approach. The outcomes demonstrate that both types of TPO in PP cause cavitation and fibrillar structures that increased the elastic and plastic work of fracture. Adding 10 wt.% ethylene- and propylene-based TPO to PP, the values of w e and βw p increase by 63%, 100% and 124%, 123%, respectively. Morphological observations show that fumed silica is located mainly around TPOs particles or at the PP/TPOs interfaces. The addition of fumed silica also reduce the size of the pores, which indicate a slight reduction in the amount of plastic work. However, fumed silica with low percentages increase the amount of elastic work and then reduce it. Also, the compound with 10 wt.% propylene-based thermoplastic elastomers and 1 wt.% fumed silica had the best toughness-stiffness-strength balance among the samples based on the optimization results.