The preparation and properties of novel structural damping composites reinforced by nitrile rubber coated 3‐D braided carbon fibers

Based on the important applications of structural damping composites in aerospace and automobile areas, novel structural‐damping composites reinforced by nitrile rubber coated 3‐D braided carbon fibers (RCF_3D/epoxy) were successfully prepared through the vacuum assisted resin transfer molding process in this work. The damping property of the composites was experimentally investigated using cantilever beam vibration test and dynamic mechanical analysis. The results exhibit that the damping loss factor of the composites obtained from cantilever beam vibration test increases by 120%, reaching 0.068 after nitrile rubber coating modification. At the frequency of 1 Hz at room temperature, the loss factor of RCF_3D/epoxy is about five times as high as that of the original composites. Furthermore, the impact strength and transverse shear strength increase by 11 and 6.8%, respectively, although the flexural strength and modulus and the longitudinal shear strength decrease slightly. The product of elastic modulus and loss factor E*η as the maximum merit index reaches 2.17 GPa. The results mentioned above indicate that rubber coating modification proposed in this work is an effective way to optimize the damping property with a negligible influence on mechanical properties of the RCF_3D/epoxy, which will be a promising strategy for obtaining structural‐damping composites. POLYM. COMPOS., 40:E599–E608, 2019. © 2018 Society of Plastics Engineers