Enhanced thermal and mechanical properties of boron-modified phenolic resin composites with multifiller system for aerospace applications

This study aims to investigate the properties of boron-modified phenolic resin (BPR) composites reinforced with glass fiber (GF) and mica, SiO₂, and glass powder (MSG) for potential aerospace applications. The BPR/MSG/GF composites exhibited improved mechanical strength, reduced shrinkage, and enhanced insulation properties at high temperatures. Specifically, exposed at 1000 °C, the impact strength increased by 108%, bending strength increased by 113%, shrinkage was reduced by 7.42%, and insulation properties were enhanced by 12.3%. Thermogravimetric analysis (TGA) revealed enhanced thermal stability, with a residue rate of 89.91% at 800 °C. The addition of glass powder, functioning as a fluxing agent, resulted in the densification of the ceramic layer. X-ray diffraction analysis (XRD) demonstrated that mica undergoes eutectic reaction with other fillers and glass powder to form the final ceramic layer. These findings indicate that BPR/MSG/GF composites can be optimized for high-performance applications requiring excellent heat resistance and mechanical strength. Further optimization of filler content and processing conditions can enhance the performance of these composites for specific applications.