Polydopamine/FeOOH-modified interface in carbon cloth/polyimide composites for improved mechanical/tribological properties

The performance of carbon fiber (CF) reinforced composites depend greatly on the interfacial structures of the fibers and matrix. Based on the problem, we proposed a novel and efficient method to improve their interfacial combination. Polydopamine (PDA) transition layer was coated on the CF by dip coating process, followed by growth of beta-FeOOH on single CF, and then polyimide (PI) was introduced by immersion method. beta-FeOOH with a special tetrahedral structure enabled more PI matrix to be embedded in the grooves, increasing the surface roughness of CF and contact area with PI. After modifying by PDA and beta-FeOOH, the tensile strength and modulus of the composite increased by 46% and 35%, respectively. In addition, tribology test verified that the better wear rate was obtained after introducing PDA and beta-FeOOH. All results proved the better reinforcing effect than the unmodified ones. This means that an alternative CF reinforced composites with high strength and wear resistance was developed.