Investigating the synergistic effects of carbon and glass fibers on the mechanical and thermal properties of phenol‐containing phthalonitrile composites

The progressive development of lightweight composites exhibiting desirable thermo‐mechanical properties is an area of growing interest, particularly with the phthalonitrile (PN) based composites, which have shown great potential. However, our understanding of the mechanical and thermal properties of the phenol‐containing phthalonitrile (PN75) resin composites often reveals limitations that make them less suitable for specific structural applications. In this work, we focused on enhancing the mechanical and thermal properties of the PN75 resin through the incorporation of the 4‐aminophthalonitrile (4‐APN), resulting in improved the curing behaviors and increased thermal stability. Our investigation of the short carbon fiber (SCF) and short glass fiber (SGF) reinforced PN75 resin composites revealed that the hybrid SCF/SGF‐based composites at 15 wt% SCF and 15 wt% SGF content exhibited an excellent tensile and the flexural strength. Additionally, the thermogravimetric analysis demonstrated maximum onset degradation and decomposition temperatures at this ratio compared with the neat resin, also we evaluated the interfacial adhesion properties of the SCF/SGF and the PN75 resin composites. These findings contribute to the advancement of polymer composite materials and expand their potential applications across various industries.