Interfacial enhancement of carbon fiber composites by poly(amido amine) functionalization

Carbon fiber reinforced composites have stimulated increasing attention due to their excellent mechanical properties. However, the interface tends to be weak because carbon fiber does not naturally have a good wettability and adsorption with most polymers matrix, which could not effectively transfer the load from the matrix to the fibers. Here we proposed to chemically functionalize carbon fiber (CF) by poly (amido amine) (PAMAM), which has more concentration of amino groups than traditional coupling agents. The chemical bond formation between acid-treated CF and PAMAM was confirmed. The PAMAM functionalization did not change the surface morphology while significantly increased the wettability of CF surface. The interfacial shear strength has an increase of 85% compared to that without functionalization. The interfacial enhancement mechanism was also explored in details.