Polyaniline-coated coconut fibers: Structure, properties and their use as conductive additives in matrix of polyurethane derived from castor oil

• Published in: Polymer testing Vol. 38; pp. 18 - 25
• Main Authors: Merlini, Claudia, Barra, Guilherme M.O., Schmitz, Débora P., Ramôa, Sílvia D.A.S., Silveira, Adriana, Araujo, Thiago Medeiros, Pegoretti, Alessandro
• Format: Journal Article
• Language: English
• Published: Kindlington Elsevier Ltd 01.09.2014; Elsevier
• Subjects: Additives; Applied sciences; Blends; Coconut fibers; Composites; Electrical conductivity; Electrical resistivity; Exact sciences and technology; Fibers; Forms of application and semi-finished materials; Intrinsically conducting polymer; Polyaniline; Polymer industry, paints, wood; Polyurethane; Polyurethane resins; Resistivity; Technology of polymers; Coconut fibers; Polyaniline; Polyurethane; Intrinsically conducting polymer; Conducting material; Electrical conductivity; Coated fiber; Aromatic polymer; Plant fiber; Coconut fiber; Vegetable oil; Polyaddition; Composite material; Castor oil; Natural fiber; Crosslinked polymer; Aniline polymer; Electrical properties; Experimental study; Pressure sensor; Surface treatment; Conducting polymers; Compressive stress; Morphology; Preparation; Oxidative polymerization
• ISSN: 0142-9418; 1873-2348
• DOI: 10.1016/j.polymertesting.2014.06.005

Electrically conducting fibers based on coconut fibers (CF) and polyaniline (PANI) were prepared through in situ oxidative polymerization of aniline (ANI) in the presence of CF using iron (III) chloride hexahydrate (FeCl3.6H2O) or ammonium persulfate (APS) as an oxidant. The PANI-coated coconut fibers (CF-PANI) displayed various morphologies, electrical conductivities and percentages of PANI on the CF surface. For both systems, a PANI conductive layer was present on the CF surface, which was responsible for an electrical conductivity of around 1.5 × 10−1 and 1.9 × 10−2 S cm−1 for composites prepared with FeCl3.6H2O and APS, respectively; values that are similar to that of pure PANI. In order to modify the structure and properties of polyurethane derived from castor oil (PU) both CF-PANI and pure PANI were used as conductive additives. The PU/CF-PANI composites exhibited higher electrical conductivity than pure PU and PU/PANI blends. Additionally, the PU/CF-PANI composites showed a variation in electrical resistivity according to the compressive stress applied, indicating that these materials could be applied for pressure-sensitive applications.