Investigation on flame‐retardant, thermal and mechanical properties of glass fiber reinforced polyimide composites

Abstract Composites with excellent flame retardant and mechanical properties are in high demand in the aerospace and various industrial fields. Glass fiber (GF) reinforced polyimide (PI) composites (GFRPCs) were fabricated using a simple ball milling and hot pressing technique. The effect of GF content on the thermal stability, mechanical and flame retardant properties of composites has been systematically studied. The Rockwell hardness of GFRPCs increase with increasing GF content, while the compressive strength, impact strength and flexural strength initially show an increase followed by a decrease due to the excellent dispersibility of the fillers and the strong interfacial interaction between the one‐dimensional GF and PI matrix. Thermogravimetric analysis results show that the addition of GF with very low thermal conductivity and excellent temperature resistance can effectively improve the thermal stability of PI. Adding GF into PI can obviously improve the limiting oxygen index value. Moreover, as the GF content increased, the time to ignition of the composites prolonged while total heat release decreased. These findings suggest a viable solution for enhancing both the flame retardance and mechanical properties of PI‐based composites. Highlights GFRPCs with high GF content fabricated via ball milling‐hot pressing method. Silane modified GF obviously improves the thermal stability of PI matrix. GFRPCs‐28 exhibits superior mechanical properties. An increases in time to ignition (TTI) and mass residual rate (MRR) of the GFRPCs was observed on adding GF.