Crystallinity, oxidation states and morphology of polyaniline coated curauá fibers in polyamide-6 composites

Polyaniline (PAni) is one of the most studied conductive polymers due to its ability to exist in various redox states. The possibility of depositing PAni on vegetable fibers and incorporating this in polymeric matrices, such as polyamide-6, enables production of antistatic reinforced materials. In this work, polyaniline was deposited on fiber surfaces on a pilot plant scale and the composites were prepared by extrusion. The microstructures of the polyaniline coated curauá fibers and polyamide-6 were characterized by X-ray diffraction (XRD) measurements and the crystallinity degree of the polyamide-6 was evaluated by differential scanning calorimetry and XRD. Atomic force and electron scanning microscopies were employed to observe the distribution and morphology of the PAni nanoparticles. The oxidation states of PAni were determined by X-ray photoelectron spectroscopy. The results showed that polyaniline supported on the fibers presents amorphous domains and nanometer scale sizes.