Evaluation of the use of açaí seed residue as reinforcement in polymeric composite

Abstract

Açaí ( Euterpe oleracea Mart.) is an important economic source in the north region of Brazil for agro-industry. However, it generates a huge amount of seed residue as agro-waste. The aim of this study is to evaluate the performance of this residue as reinforcement in particleboards. The medium-density particleboards were manufactured according to the experimental design (22 + 1), considering the parameters with two factors: “Granulometry”, for different açaí seed sizes (2.38, 1.19, 0.29, 0.15 and 0.07 mm) and “%Resin”, for different resin weight fractions (10%, 12.5% and 15%), both applied in the manufacturing of the composites. Measurements for the Apparent Density Thickness Swelling and Water Absorption (WA) of the particleboards were performed. Mechanical properties of particleboards were analyzed through top and surface Screw Withdrawal and Internal Bonding test. In addition, the morphology of surface from particleboards was evaluated through Scanning Electron Microscopy The results of TS for 24 h, WA for 2 and 24 h, and IB showed that the particle size was a significant factor ( p < .05). These results established that the highest particle sizes provided lower percentages of absorption. The results of Screw Withdrawal did not achieve the requirements established by NBR 14810–2:2018 standard. Besides that, the results presented statistical difference, considering the particle size and the interaction between parameters (“%Resin” and “Granulometry”), which resulted in a p-value < .05. For the Internal Bonding test, the composite with highest particle size exhibited the best performance compared to the other ones.