Fernando Jesus Nogara Lisboa
Abstract:
Brazil is the second largest soy producer in the world. Parallel to the high productivity there is also a high production of crop residues, which can generate the equivalent of 120 - 150% of the mass of grain residues, being 32% of this value composed of soybean pod. Mineral composites appear as a way of removing part of the large volume of waste generated by soybean cultivation and turning it into raw material for a higher value-added product. Therefore, this work aimed to evaluate the potential use of soybean pod for the production of mineral composites. For this purpose, mineral composites were produced with a consortium of Eucalyptus grandis wood with soybean pod (Glycine max). The soybean pod was inserted in the proportions of 0, 25, 50, 75 and 100% and the treatments were complemented with Eucalyptus grandis wood up to 100% of the reinforcement material mass. Both lignocellulosic materials underwent a treatment by immersion in NaOH solution (5%) for 48 hours. The composites produced were evaluated for their physical properties of bulk density, water absorption and thickness swelling at 2 and 24 hours of immersion, and their mechanical properties of modulus of elasticity, modulus of rupture, perpendicular traction, parallel compression and Janka hardness. There was no effect of soybean pod insertion on the evaluated physical properties. The composites presented average apparent density of 1.30/cm³, water absorption and thickness swelling after 24 hours of water immersion of 32.50 and 1.68%, respectively. The mechanical properties decreased with the increase of the soybean pod ratio in the panel composition and, according to the adjusted equations, the maximum value of substitution of eucalyptus wood for soybean pod was 38% so that the composites produced could meet quality standards.
