Development of wet-strength paper with dianhydride and diacid

Cellulose is the major component in papermaking. The hydroxyl groups in cellulose are easily reacted with anhydride to form an ester bond via esterification process. The addition of anhydride and diacid in cotton cellulose were found to give a good wet-strength development. The esterification process between dianhydride and hydroxyl group in cotton cellulose proceed even at room temperature. However, the reaction of diacids requires much higher temperature for the cross-linking process to occur. The FT-IR spectra in the reacted samples show bands at 1720 and 1580 cm−1, which are due to the ester carbonyl and carboxylate carbonyl, respectively. Increasing the conditioning temperature to 130 °C cause the water retention value in the reacted samples decreased tremendously. The percentage of wet-strength development for BTD and BTCA at 110 °C for 15 min treatment is 41 and 27.7%, respectively. Increasing the temperature above 110 °C has resulted the fibre to deteriorate further hence reduced the dry strength of the fibres.