The effect of wood particles polyesterification with sorbitol and citric acid on the properties of particleboard produced with the use of PF/pMDI adhesive

This study investigated the effect of pine particle polyesterification with the mixture of sorbitol and citric acid (SCA) on the properties of particleboard bonded with the PF/pMDI hybrid resin. The use of SCA with a concentration of 35% contributed to improvement in the internal bond of the particleboards, their water resistance and dimensional stability. However, lowering the concentration to 25% resulted in a deterioration of the properties of produced materials. The effect of different loadings of pMDI in the PF/pMDI resin (0%, 5%, 15%, 25%) was also investigated and the outcomes showed a positive effect of the share of 15% and 25%. Furthermore, boards made of treated particles were characterized by slightly better flammable properties (lower mass loss, flashing point temperature and delayed ignition), and the visibility of the effect increased with the increase in the concentration of the impregnate. The results also indicate that the introduction of pMDI may also influence the ignition of the board.