Investigation of the use of chitosan and carboxylic acids as a substitute for urea formaldehyde adhesive in medium density fiberboard

In the present study, the functional properties of medium-density fiber board made with formaldehyde urea resin as a control with MDF made with chitosan and carboxylic acids were investigated and compared. Various compounds including chitosan acetate solution, chitosan acetate –butane tetra carboxylic acid solution, chitosan acetate -citric acid solution and citric acid solution were investigated. The chemical structure of specimens was investigated by infrared spectroscopy (FTIR). The results of spectroscopy clearly showed the difference in the use of different compounds. The formation of cross-links between cellulose chains and carboxylic acids was confirmed, as well as the formation of hydrogen bonds between chitosan and lignin. Specimens made with the combination of acetate chitosan-BTCA showed better dimensional stability. Also, the internal bonding of MDF specimens made with chitosan acetate solution was higher than controls. Boards made of Chitosan acetate -BTCA compound can be considered as a successful substitute for urea-formaldehyde adhesive due to its better dimensional stability and good internal bonding.