Construction of polydopamine and carbon nanotube on carbon fiber surfaces to improve the mechanical properties of CF/PLA composite

Polydopamine (PDA) and carbon nanotubes (CNT) were successively incorporated onto carbon fiber (CF) to enhance surface activity. The impact of PDA and CNT on wettability and mechanical properties of the resulting composites were revealed. Fiber reinforced polylactic acid (PLA) composites were prepared. The results indicated an improved wettability for PDA-CNT modified fibers. Simultaneously, the tensile and bending curves showed brittle and plastic fracture, respectively. Mechanical properties of CF-PDA-CNT/PLA composite significantly outperformed those of CF/PLA composite. The bridging effect of PDA on the CF surface allowed for a tight bond with the matrix PLA, and provided effective load transfer between the matrix and fibers. The application of PDA and CNT on surface modification provides a novel approach for the study of fiber modification.