Interface Modification of Carbon Fiber Fabric Reinforced Epoxy Resin Composites by Polydopamine and Nano‐Silica for Enhanced Mechanical and Damping Properties

ABSTRACT In order to solve the problem of low mechanical and damping properties of carbon fiber reinforced epoxy resin (CREP) composites due to the weak interfacial bonding between carbon fiber and epoxy matrix for further expanding the application of carbon fiber reinforced epoxy resin composites in the fields of small unmanned aerial vehicles and lightweight energy‐dissipation structures operating at room temperature, the carbon fiber fabric (CFF) is sequentially coated with polydopamine and modified with nano‐silica, and then compounded with epoxy resin through vacuum assisted resin transfer molding to prepare the CREP composites in this paper. The results show that the chemical bonding between polydopamine and epoxy matrix, the mechanical interlocking effect of nano‐silica, and the abundant hydrogen bonds at the interface between polydopamine/nano‐silica and epoxy matrix could significantly improve the interfacial bonding strength between carbon fiber fabric and epoxy matrix. When the volume fraction of carbon fiber fabric treated by polydopamine and nano‐silica is 55 vol%, the CREP composite exhibits an excellent comprehensive performance balance among strength, ductility, stiffness and room‐temperature damping capacity, whose tensile strength, elongation at break, flexural strength, flexural modulus and loss factor at 25°C are 785.18 MPa, 13.38%, 608.73 MPa, 45.86 GPa, and 0.0384, respectively.