Efeitos da mercerização em fibras de Piaçava Amazônica (Leopoldinia piassaba) para produção de painéis de partículas de média densidade

Abstract

Due to demand for new economically viable and environmentally correct materials, many researches are being developed to minimize the impacts caused by exploration and production of materials from unsustainable and/or non-renewable sources. As a result, composite materials with reinforcements of vegetal fibers are being studied, in order to facilitate new sources of raw material. This research presents a study on the potential use of Amazon Piassava (Leopoldinia Piassaba) mercerized with NaOH in the production of panels of medium density particles,, using the bicomponent polyurethane resin derived from castor (Ricinus communis) oil as polymer matrix. Where made morphological, physical and chemical studies of regional piassava fibers, as well as a study of the influence of superficial modifications in the fiber caused by the alkaline mercerising treatment (NaOH). Such study has been realized at concentrations of 5% and 10% by evaluating their contributions in the adhesion of the fiber to the matrix. The fiberboards produced were classified based on experimental design, and evaluated physical and mechanically based on standards of the Brazilian Association of Technical Standards NBR 14810-2: 2013, noting the influence and interaction of factors involved: resin concentration and content of treatment. The analysis physical and morphological indicated an increase of superficial fibrillar area, as well as an increase of porosity after chemical treatment. On higher concentrations of alkaline solution (10% of NaOH) the fibers presented defibrillation. These factors probably occurred by total or partial removal of some components of vegetable fiber, such as hemicellulose, lignin, waxes and other organic extractives. Besides that, the chemical treatment provided partial cleaning on the surface of the fibers, reducing the protrusions present in the material, which are rich in silica, without compromising its structural properties dramatically. These facts contribute to the variation in the physical and mechanical properties of the panels, and consequently to increase the potentiality of the use of fibers of piaçava, as raw material in reinforcements for polymeric composites.