Thermal properties of surface-modified nano-Al2O3/Kevlar fiber/ epoxy composites

The mechanical and thermal properties of Kevlar fiber reinforced polymer composites are favorable. Researchers have extensively studied to improve these composites' mechanical characteristics, but research into improving their thermal properties is still limited. The aim of this study is to further improve the thermal properties of Kevlar fiber reinforced epoxy composite using surface modified Al2O3 nanoparticles. Vacuum-assisted resin infusion method (VARIM) was used to produce nanocomposite laminates. The surface of Al2O3 nanoparticles was modified with a silane coupling agent. Ultrasonication and magnetic mixing were used to incorporate Al2O3 at various wt.% (1, 2, 3, 4 and 5) into epoxy. Thermal stability was determined by performing differential scanning calorimetric (DSC) and thermogravimetric analysis (TGA) and measuring thermal conductivity and thermal diffusivity. The results obtained revealed that the surface-modified Al2O3 nanoparticles exhibit good thermal barrier properties and improve thermal stability. In terms of degradation temperature and specific heat capacity, the thermal stability of Kevlar composites is best at 3 wt% Al2O3. SEM images and EDX processing were used to determine the morphological characteristics. The chemical composition was confirmed by EDX analysis, and SEM images revealed that the failure occurred in fiber and matrix-related mechanisms. Fourier transform infrared (FT-IR) spectra were recorded using a FT-IR spectrophotometer. It was seen that three new peaks appear with the addition of surface-modified Al2O3.