Influência do tratamento químico na fibra de coco para utilização em compósito polimérico

Abstract

Composites reinforced with natural fibers with polymer matrices has been an attractive area for researchers and industry, which currently becomes a necessity to add value to the waste generated by the population, creating efficient alternative materials and cost, taking advantage of its own natural resources, and preserving the environment. In this study, composite materials of polyester unsaturated matrix reinforced with coconut fibers, randomly arranged, were produced using the lowest possible level of technological processes in the production stages, in order to optimize the process of mercerization in composites with coconut fiber. The polyester matrix used was pre-accelerated orthophthalic and cured with methyl ethyl ketone peroxide (MEK-P) ratio to the resin 1% by volume. The coconut fibers have been extracted from vegetation of our region and divided into 2 portions. A left in the nature state fresh and the other was divided and subjected to chemical treatment with NaOH in proportions of 0.5%, 1%, 5% and 10%. After the fibers have been manually cut in 15 mm lengths and used in environmental conditions. The composites were made by hand casting without pressure and at ambient temperature, then cured in an oven at 80 ° C for 48 hours. The coconut fibers were subjected to thermal analysis and microstructural evaluation by scanning electron microscopy (SEM). The composites were evaluated in tensile test and evaluation of the fractured surface. For composites, the larger the tensile strength were obtained for fibers treated with 0.5% NaOH and 1% NaOH. The failure mechanisms present in the polymeric composite fracture surface with coconut fiber treated with 1% NaOH were pull out (fiber pullout) and the breaking of the fibers. It is predominant disruption of the fibers, indicating that the treatment took place with the largest membership of fiber polymer matrix.