Antistatic-reinforced biocomposites of polyamide-6 and polyaniline-coated curaua fibers prepared on a pilot plant scale

Curaua fibers were used with success as a reinforcing agent in polyamide-6, however, for several applications, an antistatic dissipation property is also desirable and the incorporation of an intrinsically conducting polymer is a suitable way to promote this. The novelty of this work is the simultaneous introduction of these two properties, antistatic and reinforcement, using one filler, obtained by depositing polyaniline on the surface of short curaua fibers. Nearly 5-30 wt% of these modified fibers were dispersed by extrusion in polyamide-6, the composites were injection molded and characterized by electrical, mechanical, morphological, and rheological properties. The tensile strength of the polyamide-6 composites reinforced with 5 and 30 wt% of polyaniline coated curaua fibers, was 56% higher and 23% lower than the values obtained for pure polyamide-6, respectively. Also, the composite reinforced with 5 wt% of fibers, when processed with lower shearing rates, showed conductivity in the range of antistatic materials, 4 Scm-1. Scanning electronic microscopy and infrared spectroscopy showed an improvement in interfacial adhesion in PA-6/CF-PAni composites. The composite prepared with 5 wt% of polyaniline coated curaua fibers gave the best balance between the electrical and the mechanical properties. Extrusion and injection molding methods used here are suitable for continuous large scale production. POLYM. COMPOS., 34:1081-1090, 2013. (c) 2013 Society of Plastics Engineers