Polyaniline coated curaua fibres in polyamide-6 composites: the effect of fibre surface modification on the crystallographic properties

摘要

Composites have the ability to combine the individual properties of constitutive components, generating a unique material with properties suitable for a particular purpose. This study aims to develop a polymeric reinforced composite material, which is antistatic and light. Polyaniline (PAni) is one of the most studied conductive polymers due to its ability to exist in a large number of intrinsic redox states. The possibility of carrying out PAni synthesis on vegetable fibres and incorporating this in polymeric matrices, such as polyamide-6, enables the production of antistatic reinforced materials. In this work, curaua fibres were chemically treated with polyaniline doped with p-toluene sulfonic acid and processed with polyamide-6 in a twin-screw co-rotating and interpenetrating extruder. The microstructures of the neat curaua fibres and polyaniline coated curaua fibres were characterized by X-ray diffraction (XRD) measurements. Scanning electron microscopy was employed to observe the distribution and morphology of the PAni nanoparticles. The oxidation states of PAni were evaluated by X-ray photoelectron spectroscopy. X-ray diffraction combined with microscopy analyses of PAni synthesized without a substrate, showed crystalline components embedded into amorphous regions in the sample, while the PAni synthesized on the fibres showed a lower degree of crystallinity. The XPS analysis shows that the PAni synthesized on the fibres is in the emeraldine salt form.