Bonding ability of a new adhesive composed of citric acid-sucrose for particleboard

Citric acid is a potential binding agent for composite products that has three carboxyl groups that can be ester linked with the hydroxyl groups found in wood. The addition of sucrose provides hydroxyl groups and increases the amount of ester groups. This research investigated the bonding ability of a new adhesive composed of citric acid-sucrose for teak particleboard. Citric acid and sucrose were dissolved in water under various ratios, and the concentration of the solution was adjusted to 59 to 60 wt%.This adhesive solution was sprayed onto the particles at 10% resin content based on the weight of air-dried particles. Each mixture was then hot pressed at 180 and 200 °C for 10 min. The physical and mechanical properties of the particleboards were tested, and the results showed that increasing the pressing temperature affected the dimensional stability. However, increasing of citric acid in adhesive composition improved the dimensional stability and mechanical properties of the particleboards. The optimum properties of the board were achieved at a pressing temperature of 200 °C and addition of only 10% citric acid. The results also indicated that the peak intensity of C=O group increased with the addition of citric acid and increasing pressing temperature, indicating that ester linkage occurred. However, the addition of sucrose did not greatly affect the peak intensity of C=O group.