Ecofriendly panels for building with eucalyptus sawdust and vegetal polyurethane resin: A mechanical evaluation

The use of natural fibers in composite materials has become an alternative to use synthetic ones. With the increase in consumption and the generation of waste, it becomes interesting to search for alternatives friendly to environment. The objective of this work was to evaluate the mechanical properties of composites manufactured using residues: from the wood industry (eucalyptus sawdust), from red ceramic (chamotte), and a vegetable based resin (castor oil-based polyurethane resin) as a matrix. The composites were manufactured in volumetric fractions of 70, 75, 80 and 85 of eucalyptus sawdust; and 0, 5 and 10% of chamotte, totaling 12 formulations. Scanning electron microscopy (SEM) analyzes were performed on the eucalyptus sawdust used and on the composites produced with and without chamotte. The results indicates that both for the modulus of elasticity and modulus of rupture, the increase in the volumetric fraction of chamotte incorporated at composites causes an increase of properties in all compositions studied. In perpendicular tensile testing, it obtained values between 1.910 and 3.449 MPa. In the izod impact testing, values between 47.61 and 115.44 J/m were obtained. It was observed on SEM images that with the incorporation of chamotte on composites there was a great reduction in the amount of bubbles and voids presented at polymeric matrix and in some compositions have increased also the mechanical properties. Thus bringing a new option for use and adding value to this residue from the ceramic industry, producing an ecofriendly composite panel.