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

Abstract

Curauá 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 curauá 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 curauá 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 μS cm−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 curauá 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. © 2013 Society of Plastics Engineers

Elastomer composite based on EPDM reinforced with polyaniline coated curauá fibers prepared by mechanical mixing

“…[13][14][15] A similar behavior was reported for composites of nylon-6 reinforced with PAni coated curau a fibers; above a certain concentration of the filler the composites become brittle. 38 From these results, it is clear that is not possible in these composites to optimize both properties simultaneously, conductivity, and tensile strength. However, at 30 wt % of CF-PAni it is possible to reach the highest conductivity with about 50% loss in the mechanical properties of the EPDM/CFPAni composites.…”

“…PAni addition increases the compatibility between fiber and matrix due to hydrogen bond formation at the interface. 38 The modified fibers present better results of tensile strength in comparison to the unmodified fibers, indicating that PAni induces a stronger fiber-matrix interaction. Quinoid and benzenoid segments of PAni interact by van der Waal forces with nonpolar chains of the EPDM matrix (Figure 8) while the nitrogen atoms of PAni are responsible by strong interactions with curau a fiber surface, producing hydrogen bonds between aminic nitrogens and the acidic groups of lignin (carbonyl groups) and iminic nitrogens of PAni and the hydroxyl groups of the fiber surface.…”

“…Before the polymerization reaction, aniline was distilled under vacuum at 130 C. The synthesis of PAni directly on the curau a fiber surface was performed based on our previous works, 13,37,38 maintaining the same monomer and oxidizing agent ratio ) were added dropwise, while the mixture was kept under mechanical stirring at 25 C by pumping a cooling solution through the reactor jacket. After the color changed to dark green, the resulting mixture was removed from the reactor, filtered and washed with a 2 : 5 (v/v) water : ethanol solution.…”

Preparation and characterization of composites from plastic waste and sugar cane fiber

“…60% PWH/40% sugar cane fiber (our study) 7.6 ± 0.7 18.1 ± 0.4 57.5 ± 4.0 13.9 ± 0.5 1-80% Epoxi resin/15% FBC/5% glass fiber [13] 4.69…”

“…On the other hand, the abundance of natural fibers such as sisal, coconut, jute, ramie bast, eucalyptus pulp, banana, hemp, flax, pineapple leaf, bamboo, palm, cotton, waste of mate-tea and sugarcane fiber among others and the possibility of using these fibers as reinforcement in composites stimulate the studies of different products combining these raw materials [11][12][13][14][15] . Each of these natural fibers has a wide range of mechanical and physical properties governing its wider applications.…”