Desenvolvimento, caracterização e prototipagem de compósitos poliméricos estruturados com fibra de matamatá para aplicação em mobiliário ecoamigável

Abstract

The urgent need to mitigate the drastic environmental impacts on ecosystems is essential for planetary conservation. In this context, this research reports integrative methods for producing sustainable polymer composites using hand-molding techniques, using fiber extracted from the bark of the Matamata tree combined with a thermosetting matrix, for use in home furnishings. Initially, the fiber was characterized physicochemically and morphologically using geometric density, vibrational infrared spectroscopy (FTIR), thermogravimetry (TGA/DTG), differential scanning calorimetry (DSC), X-ray diffraction (XRD), scanning electron microscopy (SEM), and tensile strength. The mechanical properties of composites (CPs) manufactured with 10, 20, and 30% vol fibers were determined through IZOD tensile, flexural, compression, and impact tests, and fractography of the samples was performed using SEM. The mechanical data collected from the fiber and CPs were validated by ANOVA and Tukey's test. To evaluate the application feasibility of the obtained material, an integrative prototyping strategy was used to obtain a seat. Consequently, the fiber demonstrated a low average density of 0.38 ± 0.14 g/cm³ and an average tensile strength of 58.82±8.18 MPa. FTIR spectra detected groups characteristic of natural fibers (–OH, C=C, C=O, C–H). TGA/DTG/DSC thermoanalytical analyses revealed high thermal stability of the fiber up to 486 °C. XRD analysis provided a crystallinity index of 63.54% and a microfibrillar angle of 6.12°. Through mechanical tests, the CPs added with 10, 20 and 30% vol of fiber, exhibited favorable results in relation to the isolated matrix, with the highest resulting values for Tensile (30% = 45.73 ± 3.07 MPa), Flexure (30% = 66.03 ± 3.23 MPa), Compression (20% =182.376 ± 9.71 MPa) and IZOD impact (30 %=30.69 ± 0.41 J/m). Thus, the 20 and 30% vol CPs exhibited the best results. However, in all cases, the 20% vol CPs presented comparable mechanical properties, combining toughness with greater strength due to the better dispersion of the fibers in the matrix, making it more suitable for the manufacture of domestic seats. This was demonstrated by the prototyping and cost analysis of the seat, which presented a direct cost of R$ 23.71, efficiency and convenience factor equal to 0.053 and 0.977, with the total estimated price of the bench equal to R$ 297.54. Therefore, in addition to its lightness due to the application of a low-density fiber, the manufactured seat presents a unique ergonomic design, differentiating itself from the state of the art by integrating structural efficiency, practical functionality, and sustainable use of Matamata fiber in its natural state, applied in a single module. It is intended for the A47 technology sector, for the manufacture of domestic furniture.