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.

Acai Residue as an Ecologic Filler to Reinforcement of Natural Rubber Biocomposites

“…is one of the most important fruits of plant extraction in the Amazon region and the consumption of its pulp has increased more and more in the national and international markets 1 . In 2020, 220 thousand tons of acai fruit were produced, with Pará being the largest producer in the Brazilian state 2 . However, only 20% of the fruit is used in the form of pulp by the food 3 , pharmaceutical 1 , biomedical 4 , and cosmetics 5 industries, so approximately 176 thousand tons are waste discarded in landfills by the agroindustry 6 .…”

“…Oliveira et al 6 , evaluated the changes in density, chemical structure, morphology, water absorption, porosity, and thermal and mechanical properties in castor bean-based polyurethane reinforced with acai residue (5-20% by weight). Barbosa et al 2 , evaluated the performance of acai residue as reinforcement in agglomerated panels and made the panels considering two factors: granulometry and different fractions of resin. Lima et al 1 , analyzed the potential of the residual biomass of acai in biotechnological applications, such as fermentation processes and the production of fermentable sugars (mannose) for food and pharmaceutical purposes, for this, they characterized the samples in different states of maturity.…”