Effect of the addition of lignin on the physical-mechanical properties of particleboards made with pine/hydrangea stems

The effect of adding different lignins on the physical and mechanical properties of particleboards made with stems of hydrangea and pine using the urea-formaldehyde (UF) resin was evaluated. Four types of lignin were characterized by Fourier-transform infrared spectroscopy and Klason lignin: Cane Bagasse lignin, Pine China lignin, Kraft Brazil lignin, and ammonium lignosulfonate (LSA). Particleboards were prepared with four types of lignin in a 1:1 (w/w) UF/lignin ratio and compared with those prepared with the UF resin without lignin (control sample). Water absorption, thickness swelling, rupture modulus, and modulus of elasticity were measured. The type of lignin used does not have a statistically significant difference in the physical and mechanical properties and also a decrease in the physical properties of the particleboards compared with the control sample. The use of LSA in the 3:1 (w/w) UF/lignin ratio allows to elaborate particleboards with mechanical properties like those found in the control sample.