Effect of O ‐ C ₃ N 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.