Painéis de partículas com resíduo agroindustrial mercerizado: caracterização das propriedades físico mecânicas.

Abstract

The present work aims to motivate the application of agro-industrial residue in the production of particleboards, involving the production of a new product with a sustainable nature. The study focuses on the use of andiroba cake extraction, a by product obtained after removing the oil from the fruit seeds, which has no viable destination. Mercerization was applied to improve the adhesion of the destruction particles to the polymer. Polyurethane resin derived from castor oil was chosen for its good performance as a polymeric matrix and partially sustainable nature. Five types of panels were produced via thermal pressing, using treatment treated with 5% sodium hydroxide (NaOH), varying the resin weight proportion (15, 20 and 25%) and processing temperature (110, 120 and 130 ºC), in order to evaluate the influence of these processing parameters on the physical-mechanical properties of the composites. The untreated and treated residues were characterized via X-ray Diffraction (XRD) and Fourier Transform Infrared Spectroscopy (FTIR). The properties of the panels were evaluated through physical (Swelling and Density), mechanical (Three-point Bending) and morphological (SEM - Scanning Electron Microscopy) characterizations. XRD results indicate that NaOH treatment slightly increased the crystalline index, but may not have been completely effective in removing non-cellulosic components. Analysis of FTIR spectra corroborated with these observations, showing only small changes in the functional groups after treatment. The particleboards presented good physical properties, with a low swelling percentage, due to the hydrophobic nature of the resin and the high content of residual oil in the waste. Regarding the influence of processing parameters, panels with a higher resin proportion and higher pressing temperature during processing had higher nominal density values, as well as a more uniform and regular surface (as shown in the SEM micrographs), which suggests that these parameters result in greater densification. Furthermore, panels with higher resin concentrations and temperatures had better mechanical performance.