High-performance fiber-reinforced composites using cardanol-based resin and epoxy resin blend: mechanical, thermal, morphological, and chemical resistance properties with various hardeners

This study explores fiber-reinforced composites (FRCs) using a 70:30 blend of cardanol-based resin and epoxy resin (EEW 190) with six different hardeners: diethylenetriamine (DETA), triethylenetetramine (TETA), meta-xylylenediamine (MXDA), isophorone diamine (IPDA), polyamide and polyamidoamine. Composites were fabricated using jute fiber mats (eco-friendly, lightweight, suitable for packaging and low-load structural panels), woven glass fabrics (moderate strength and stiffness, ideal for marine and construction applications), and woven carbon fiber fabrics (high strength and thermal stability, applicable in aerospace and automotive structures) as reinforcements and characterized for thermal stability, mechanical performance, morphological properties and chemical resistance. Thermogravimetric analysis (TGA) and differential thermogravimetric analysis (DTGA) demonstrated superior thermal resistance for carbon fiber composites, retaining up to 80% of their weight at 500°C, followed by glass and jute composites. Mechanical testing revealed that carbon fiber composites exhibited the highest tensile (83.3 MPa), flexural (223.5 MPa) and impact strength (9.75 J/cm), significantly outperforming glass and jute composites. Morphological analysis using scanning electron microscopy (SEM) confirmed strong interfacial bonding and minimal voids in composites cured with polyamidoamine, while rigid hardeners (DETA, TETA) led to brittleness and micro-cracks. Chemical resistance testing highlighted carbon fiber composites exceptional stability, maintaining structural integrity across various chemical environments.