Effect of <scp>O</scp> ‐ <scp>C</scp> ₃ <scp>N</scp> ₄ on the mechanical properties of glass fiber/epoxy resin composites

Abstract The interfacial bonding between fiber and matrix is very important for the mechanical properties of composites. This effort involved oxidizing C 3 N 4 to produce O‐C 3 N 4 , which was employed to improve the mechanical and thermal properties of glass fiber/epoxy composites. The microstructure and reinforcement mechanism of O‐C 3 N 4 modified glass fiber/epoxy composites (O‐C 3 N 4 /GF/EP) were analyzed by SEM, contact angle, mechanical properties, and dynamic mechanical analysis (DMA). The results show that the O‐C 3 N 4 /GF/EP composites with 0.5 phr O‐C 3 N 4 have the best mechanical properties. The interlaminar shear strength, tensile strength, bending strength, and impact strength of the composite were increased by 12.3%, 15.6%, 15.3%, and 14.7%, respectively, compared with the pure GF/EP composites. When the content of O‐C 3 N 4 is 1.0 phr, the storage modulus and the Tg of the composites were increased by 20.1% and 4.44°C, respectively. Therefore, O‐C 3 N 4 can be considered a candidate as an interfacial modifier to improve the mechanical and thermal properties of the composites. Highlights Carbon fiber composites have a wide range of applications. O‐C 3 N 4 was used to improve the mechanical properties of GF/EP composites. O‐C 3 N 4 has abundant oxygen‐containing functional groups The preparation process of O‐C 3 N 4 is simple.