Experimental analysis of tensile properties and essential work of fracture of fumed silica filled polypropylene toughened with thermoplastic polyolefin elastomer

Abstract

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.

Fracture toughness of PA6/POE‐g‐MA/TiO2 ternary nanocomposites according to the essential work fracture method

“…It is accepted that the values of w e,y can be considered as the resistance to crack initiation before yielding, and the values w e,t can be considered as the resistance to crack propagation before yielding. [ 47,67 ] This means that in all the ternary nanocomposites of the present study, except for the P10E4T and P20E2T specimens, the value of w e,t was larger than w e,y . This means that most of the related energy to break the samples was spent on resisting crack propagation.…”

Mechanical behavior and essential work of fracture of surface‐modified exfoliated graphite filled polypropylene/ethylene‐vinyl acetate blend nano‐composites

“…due to its good chemical resistance, easy processing, high thermal stability, and low cost. Against these appropriate properties, the sensitivity to notch and the low toughness of this polymer, especially at low temperatures and high deformation rates limits its usage in industries 1–3 …”

“…and high deformation rates limits its usage in industries. [1][2][3] Among the existing methods to achieve the desired properties, the combination of two or more polymers is an effective and popular approach to enhance the properties of polymers at a comparatively low cost in comparison to the synthesis of new polymers. 4 The properties of blend polymers are largely depended on the phase morphology.…”

Effect of silicon dioxide and organized montmorillonite on the crystalline morphology and dielectric properties of polypropylene‐based composites

“…[4] Still, its toughness can be significantly improved by blending with hightoughness thermoplastic elastomers. [5][6][7][8] Polyolefin elastomer (POE), a thermoplastic elastomer synthesized by metallocene catalysts, possesses excellent mechanical and processing properties and is frequently used for toughening PP. However, the blending of POE with PP induces steric conformational defects in PP, which can reduce the blend's dielectric properties.…”