Synergistic behavior of dual filler system (n-Si3N4/COOH-MWCNT) on the mechanical, tribological, curing, and corrosion characteristics of epoxy hybrid nanocomposites

Abstract

Epoxy hybrid nanocomposites reinforced with silicon nitride nanoparticles (SiN) and carboxylic acid-modified multiwalled carbon nanotubes (COOH-MWCNT) were prepared by hand layup. These hybrid nanocomposites have not undergone thorough investigation in the fields of mechanical, tribological, and corrosion-resistant characteristics. The 0.25/0.5 SiN/MWCNT hybrid nanocomposite displayed improvement in elongation by 190% and fracture toughness by 360%. The effect of dual filler system on the wear and friction properties of the composite was investigated. The influence of silicon nitride and hybrid fillers the curing characteristics of epoxy was examined using Fourier transform infrared spectroscopy (FTIR). From differential scanning calorimetry (DSC), it was found that the use of dual fillers in the epoxy system reduced the residual heat of reaction and curing time by 15%. In a highly corrosive environment (3.5% NaCl), TAFEL polarization showed that 0.5/0.5 SiN/MWCNT epoxy hybrid coating on mild steel (MS) increased protection against corrosion by 30%. The dispersion of nanofillers and their interactions were verified using high-resolution transmission electron microscopy (HR-TEM). The morphology of the fracture, wear, and corroded surfaces were examined by field emission scanning electron microscopy (FE-SEM). SiN manifested a synergistic effect with MWCNTs making it a superior reinforcement at very low content.