Background: One of the major issues of carbon fiber reinforced polymeric composites is
the weak interface between the phases, that supports crack propagation and leads to premature mechanical
failure. The paper presents a study involving carbon fiber compatibilization with the polymeric
matrix via oxidative treatment and the effect that the modified carbon fiber fabric has on the mechanical
performance of its polyamide 6 composites.
Methods: Thermoplastic polyamide 6 matrix/fabric based composites are obtained using carbon fiber
fabric that is oxidized using K2Cr2O7/H2SO4 mixture in different reaction conditions. The oxidized carbon fiber surface is
analysed using FTIR spectroscopy and the composite materials are mechanically tested in terms of tensile and flexural
properties, the fracture cross section is analyzed by SEM and optical microscopy to evaluate the interface and the fracture
Results: FTIR spectroscopy showed that higher temperature oxidation generates more functional groups on the carbon
fiber surface that are able to interact with the polymer, enhancing the interface strength. Tensile and flexural tests showed
significant improvement of strength and stiffness when using surface oxidized carbon fabric, results owned to the
excellent bonding between the matrix and the fibers that compose the fabric, illustrated by SEM and optical microscopy
Conclusion: The obtained results prove that carbon fiber oxidation in certain condition is efficient for achieving stronger
fiber/themoplastic matrix interface, by creating hydrogen bonding sites that prevent delamination and are able to improve
the mechanical performance of the composites.