Enhancing the Mechanical and Fire-Resistant Properties of GFRP Composite using Boric Acid and Sodium Silicate Fillers

Abstract

This study investigates the effects of Boric Acid (BA) , H3BO3, and Sodium Silicate (SS), Na2SiO3, as single fillers on the mechanical and fire-resistant properties of Glass Fiber Reinforced Polymer (GFRP) composites. Various compositions of BA and SS were incorporated into the GFRP matrix, and the resulting composites were analyzed using X-ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), Thermo-Gravimetric Analysis (TGA), and Differential Thermal Analysis (DTA). The results demonstrate that BA significantly enhances the amorphous structure and mechanical strength of GFRP composites, with optimal performance at 10% BA content. In contrast, SS improves thermal stability but reduces mechanical strength at higher concentrations due to agglomeration. Fire resistance testing revealed that both fillers increase the ignition time and decrease the burning rate, with BA exhibiting superior performance. These findings suggest that BA is a more effective filler for improving the mechanical and fire-resistant properties of GFRP composites, while SS can serve as a complementary additive to enhance thermal stability.