Preparation and Mechanical Properties of Epoxy‐Based Carbon Fiber Composites With Dual‐Component Synergistic Modification

ABSTRACT Carbon fiber reinforced epoxy resin matrix composites (CFRP) are widely used as key structural materials in aerospace, transportation, new energy, and other fields due to their high specific strength, low thermal expansion coefficient, good thermal conductivity, and other advantages. In this study, CFRP laminates were fabricated by vacuum‐assisted resin transfer molding (VARTM) using epoxy resin (EP) modified by hydroxyl‐terminated liquid butadiene‐acrylonitrile rubber (CTBN) and nano‐cerium oxide (n‐CeO ₂ ) as the matrix, and carbon fiber as the reinforcement. Under the modification of single‐component and two‐component epoxy resins, the effects of modified resin matrix on the properties of composites were investigated through tensile tests, compression tests, bending tests, low‐velocity impact tests and compression after impact (CAI) tests. Meanwhile, the fracture surfaces of the composites were further analyzed to characterize the fracture morphology and toughening mechanism. The results show that compared with the composite with pure resin matrix (CF/E501), the tensile strength, compression properties, flexural strength and compression after impact strength of the composite with two‐component modification (CF/E504) are increased by 32%, 78%, 22% and 53%, respectively. In addition, under the impact energy of 40 J, the maximum impact load of CF/E504 is 30% higher than that of CF/E501. The addition of modifiers can enhance the impact toughness and mechanical properties of the matrix, improve the interfacial bonding between fibers and the matrix, and reduce the cracking risk of the resin matrix.