WOOD RESEARCH Volume 70, Number 1, 2025
YINLUAN QIN, XIAOLI PANG, LONGHAI CHEN, XIAORONG ZHENG, WENBANG WEI, DAJUN LONG, and JING TANG

ENHANCED PERMEABILITY OF EUCALYPTUS CLOEZIANA BASED ON NAOH/Na2SO3 AND H2O2 TREATMENTS

The synergistic effects of NaOH/Na2SO3 and H2O2 treatments on enhancing the permeability of Eucalyptus cloeziana wood were investigated. Treated and untreated specimens were analysed for pore size, microstructure, and chemical composition. The results showed that the treated wood had significantly increased average pore sizes and was characterised by cracks in the wood pits. Additionally, the contents of hemicelluloses and lignin structural components decreased, enhancing permeability. The treated wood showed a 1.2- to 1.8-fold water absorption rate higher than untreated wood. These changes result from the reaction of NaOH/Na2SO3 and H2O2 with wood

WOOD RESEARCH Volume 67, Number 1, 2022
YINLUAN QIN and LONGHAI CHEN

Effects of modification with melamine–urea–formaldehyde resin on the properties of urea pretreated eucalyptus

Eucalyptus urophylla was treated with melamine-urea-formaldehyde resin (MUF) after pretreatment with urea solution. The properties of the wood were then determined. The weight percent gain (WPG) and, antiswelling efficiencies (ASE) of the wood treated with urea+MUF were 14% and, 45% higher than those of untreated wood, respectively. The water absorption (WA) of the wood treated with urea+MUF was decreased approximately 50% lower than that of the untreated wood. However, the mechanical properties of the wood treated with urea+MUF were weakened due to the destruction of the structure of wood. An X-ray photoelectron spectroscopy (XPS) analysis revealed that the atomic concentration ratio of O/C was increased. The ratio of C1 was decreased as the lignin and extractives contents were decreased, while the ratios of C2 and C3 were increased. The urea solution pretreatment was conducive to the impregnation of wood functional modifiers.