Propriedades de painéis aglomerados de madeira com a substituição de Pinus oocarpa por resíduo de babaçu (Attalea SPP.)

Abstract

Wood particleboards, widely used in the furniture, coverings, and civil construction sectors, play an essential role in optimizing the use of forest resources and promoting sustainability. The continuous improvement of their physical, mechanical, microstructural, and thermal properties has driven the search for alternative raw materials. In this context, the present study aimed to evaluate the properties of lignocellulosic composites produced on a laboratory scale by gradually incorporating Attalea spp. residue as a substitute for Pinus oocarpa in proportions of 0, 25, 50, 75, and 100%. The Pinus oocarpa particles and Attalea spp. residue were processed and classified to obtain the desired particle size distribution. The panels, measuring 25 × 25 × 1.5 cm with a nominal density of 0.75 g/cm³ (medium density), were manufactured using 90 g of urea–formaldehyde adhesive per unit. A manual pre-pressing was first carried out at room temperature under a pressure of 0.42 MPa, followed by hot pressing under the following parameters: 10 minutes, 4 MPa, and 150°C. The chemical properties of the lignocellulosic materials were analyzed. The physical properties of the panels were evaluated through tests of apparent density, compaction ratio, water absorption, thickness swelling, and thickness recovery rate. For the mechanical properties, static bending (modulus of rupture and modulus of elasticity) and internal bond strength tests were performed. Microstructural characterization was conducted using scanning electron microscopy and stereoscopic microscopy with fluorescence. The thermal properties of the panels were also analyzed. The treatment with 50% substitution showed the best performance in thickness swelling and thickness recovery rate, while the treatment with 25% substitution exhibited satisfactory mechanical results, achieving the highest internal bond strength. The panels containing 75% substitution presented the best thermal conductivity performance. Overall, all treatments met the requirements of technical standards for particleboards intended for indoor use under dry conditions, demonstrating the technical and environmental feasibility of using Attalea spp. residue as a sustainable alternative raw material for particleboard manufacturing.