Abstract

The effect of formaldehyde scavenger on the curing behavior, bonding strength, formaldehyde emission and chemical characteristics of urea-formaldehyde resin (UF) for the particleboard manufacturer were investigated. The formaldehyde scavenger was added to UF resin at 0, 6, 12, 18 and 24 % w/w. The cure behavior of UF resin on a wood substrate containing different formaldehyde scavenger content was evaluated by differential scanning calorimetry (DSC). The results indicated that the reaction enthalpy (δH) and peak temperature (Tpeak) decrease with the increase of formaldehyde scavenger content. Notable, the δH and Tpeak values decreased up to the formaldehyde scavenger content of 12 % w/w and then were rather constant with its further addition. To determine properties, the laboratory-made particleboards bonded with UF resin at various contents of formaldehyde scavenger were manufactured. The results showed that the addition of formaldehyde scavenger could improve bonding strength of the panels and greatly reduced their formaldehyde emission. The particleboard properties were relatively stable with the further addition of formaldehyde scavenger more than 12 % w/w. The Fourier Transform Infrared Spectrophotometer (FTIR) spectra of particleboards showed variations of methylene and methylene-ether bridges which were corresponded to the curing characteristic and board properties. The corrected area under absorbance of methylene bridge increased with the increasing of formaldehyde scavenger content.