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 theratios of C2 and C3 were increased. The urea solution pretreatment was conducive to theimpregnation of wood functional modifiers.