Investigation of the effect of nanosilica on mechanical, structural, and fracture toughness of polyvinylidene fluoride films

Abstract

This work presented fabrication and characterization of the polyvinylidene fluoride (PVDF) composite material containing various contents of nano-silica (SiO2). The effects of SiO2 contents and notched forms, e.g., V-notched and U-notched single tensile, on the mechanical properties of composite films are investigated. The experimental results show that when an inevitable crack appears in the material and can’t be repaired, trimming the sharp angular crack into a circle can increase the tensile strength by 10%–35%. The stress of the film reaches the maximum value of 35.872 MPa, the elastic modulus is 2.131 GPa and fracture toughness is 2.747 MPa•m1/2 when the filling amount of SiO2 is 6%. But with increasing of SiO2 content, failure behavior of the materials becomes more and more brittle. Then, morphology of the micro-structures is analyzed by electron scanning electron microscope. It is found that the addition of SiO2 doesn’t affect the structure of the films, and it is helpful to increase the number of film pores.