Potencial de utilização de nanofibrilas de celulose em substituição ao adesivo ureia-formaldeído na produção de painéis aglomerados

Abstract

The use of nanotechnology in the development of sustainable, renewable and biodegradable materials for different industrial applications is increasing. In this sense, nanocellulose has been arousing interest due to its exceptional characteristics at the nanoscale. This abundant nanomaterial, produced from lignocellulosic biomass, is a promising alternative in the quest to replace synthetic adhesives derived from non-renewable sources. In this context, the objective of this research was to evaluate the effect of replacing (20, 40, 60 and 80%) of the urea-formaldehyde (UF) adhesive by cellulose nanofibrils (NFC), in addition to a control treatment, consisting of particle boards glued with UF-based adhesive. NFC at a concentration of 2.0% by weight was obtained via mechanical defibrillation. 10% UF adhesive, 2% NFC suspension and 1% paraffin were used. The panels were produced with a nominal density of 0.79 g cm-3 and dimensions of 15 x 15 x 1 cm (length, width and thickness, respectively). Three repetitions were adopted. Hydraulic cold pressing at 1 MPa for 10 minutes was used, followed by hot pressing of 4.0 MPa at 150 °C for 15 minutes. The properties of bulk density, compaction ratio, moisture content, water absorption and swelling in thickness (2 and 24 hours), resistance to static bending modulus of elasticity (MOE) and modulus of rupture (MOR) and perpendicular traction were evaluated (TP). Based on the results, it can be concluded that as the proportion of NFC in the panels increased, there was greater water absorption and swelling in thickness, as well as a reduction in mechanical properties (MOR, MOE and TP). The apparent density, moisture content, swelling in thickness, static bending and perpendicular traction properties met the minimum requirements determined by the ANSI A208.1 (2009) standard. The results obtained in this research indicate the replacement of up to 31% of cellulose nanofibrils in the production of particleboard.