Improvement of Eucalyptus urophylla Wood Permeability via Urea Treatment
Keywords:Urea solution, Eucalyptus urophylla, Permeability, Mechanism
To increase the loading amount of modifier in wood, a simple and universal approach was developed to improve its permeability. The generated pores in wood can be backfilled with modifiers, thereby improving the function of wood. This study aimed to improve the permeability of Eucalyptus urophylla wood using a urea solution. The wood was treated under different conditions, including urea concentration, treatment duration, and temperature, and the wood permeability before and after treatment was measured using water absorption as an indicator. The treatment temperature and solution concentration had considerable effects on the water absorption capacity of the treated wood. The treatment of eucalyptus wood with a 5% urea solution for 12 h, under normal pressure, resulted in the optimal effect; water absorption reached 40%, which was 78.9% higher than that of the untreated eucalyptus. Fourier-transform infrared spectroscopy, component analysis, and BET analysis were performed to examine the mechanism underlying the effect of urea treatment on eucalyptus, which is as follows: a weak alkaline solution can dissolve the internal components of wood, namely, hemicellulose, lignin, and alcohol-benzene, which leads to the destruction of the microstructure of the wood and increases the number of micropores and mesopores in the wood.