Estudo da utilização do adesivo à base de resíduo de EPS e solvente D-limoneno em peças de madeira lamelada colada

Abstract

The objective of this study is to characterize an adhesive produced from Expanded polystyrene (EPS) waste dissolved in D-limonene solvent for the production of structural glued Laminated Timber (GLULAM) using Eucalyptus urograndis wood. This work aligns with the global trend of reducing formaldehyde use and promoting sustainable, less harmful products. To achieve this, the physical properties of the wood—moisture content and density—were first characterized. The adhesive was prepared with a 1:1 ratio by weight of EPS residue and D-limonene solvent. For technical feasibility analysis, three different spreading rates (150g/m2,200g/m2, and 250g/m2) and two moisture content conditions were used. For each treatment, 12 specimens were prepared, totaling 72 samples. After bonding, shear tests were performed on the glue line according to ASTM 905D standard. The results showed the wood had an average moisture content of 18% and a basic density of 612.49kg/m3. The adhesive presented an average viscosity of 3,308 mPas, a solids content of 43%, a pH of 5.86, and a gel time of 158 seconds. Shear strength values did not significantly change with varying spreading rates, with the best averages achieved at 150g/m2 in the wet condition and 250g/m2 in the dry condition. The dry condition also yielded the highest strength, with an average value of 1.42 MPa, highlighting the influence of moisture on the adhesive. Optical microscopy and Scanning Electron Microscopy (SEM)were used to visualize the wood-adhesive interface, which allowed for the identification of failures in the glue line. For use in GLULAM components, the adhesive showed favorable physicochemical properties, but further formulation optimization is needed to improve its rheological characteristics.