Fracture toughness and deformation mechanism of polypropylene/styrene butadiene rubber/silicon carbide nanocomposites

Abstract In this study, the effect of the synergistic combination of styrene butadiene rubber (SBR) and silicon carbide (SiC) nanoparticles on the polypropylene (PP) matrix was studied. To do so, the fracture behavior of the PP/SBR binary blend and its nanocomposites with SiC nanoparticles was investigated. The essential work of fracture (EWF) method was used specifically to analyze the deformation mechanisms and fracture toughness of these compounds. The dominant mechanism of fracture in all ternary compounds is the shear band development as a result of SBR particles' debonding from the PP matrix, which creates a fibrillar structure. By adding SiC nanoparticles to the thermoplastic elastomer blend, the fracture toughness parameters in essential and nonessential work of fracture (i.e., and , respectively) in all ternary compounds decreased, whereas the consumed energy by yielding in essential and nonessential work of fracture (i.e., and , respectively) in all ternary compounds increased: These parameters in the ternary compound with 15% SBR and 3% SiC nanoparticles (R15N3) increased by 26.30% and 10.71% in comparison with the binary compound with 15% SBR (R15), respectively. Therefore, as a result of the EWF method, the synergistical combination of SiC nanoparticles and SBR in the PP matrix with empirical investigations of the ternary blend microstructure can produce nanocomposites while striking a balance between stiffness and toughness. In all compounds, the dissipated energy in the necking area is more than that of the yielding area. So, these compounds have a ductile behavior and stable crack extension. Highlights Most consumed energy in EWF is shear yielding, cavitation, and plastic deformation. The necking components of EWF mainly control the fracture behavior of all samples. By SiC addition, the yielding and necking values increase and decrease, respectively. By intensive aggregation of SiC nanoparticles, all the EWF parameters decrease. By SBR addition, the yielding and necking values decrease and increase, respectively.