Synergistic effect of tung oil and heat treatment on surface characteristics and dimensional stability of wood

Wood is a sustainable biomass material with undesirable intrinsic properties of hygroscopicity and dimensional instability, which restrict its broader application. Tung oil, as a natural plant oil, has shown some promise for improving wood properties. Here, a synergistic method combined with tung oil impregnation and heat treatment was used to modify wood. The results showed that both heat treatment and tung oil impregnation were helpful in decreasing the moisture absorption, water uptake, and volume swelling coefficient of wood. Moreover, the impregnated tung oil occupied the water passages and significantly reduced the porosity and permeability of wood, providing a better hydrophobic surface and thus preventing water absorption and further improving dimensional stability. Therefore, joint modification of wood by tung oil and heat treatment provides an effective and eco-friendly method that has great prospects for the future.