Effect of Ammonium Dihydrogen Phosphate (ADP) Addition as Catalyst on the Curing Maltodextrin Adhesives Properties

Abstract

Ammonium dihydrogen phosphate (ADP) is expected to be an effective catalyst to increase the water-resistance and hasten the curing speed of maltodextrin as wood adhesives. This research investigated the effect of ADP addition on the curing maltodextrin properties. The ratio of maltodextrin/ADP was 100/0 and 90/10 wt%. The heat treatment was 180-220 °C for 10 min. The water-resistance improvement and the chemical changes were analyzed using insoluble matter rate against boiling water and Fourier Transform Infrared (FTIR) analysis, respectively. The thermal behavior of the dried mixture of adhesives was also analyzed through differential scanning calorimetry (DSC) analysis at room temperature until 400 °C. The results showed that the water-resistance properties of maltodextrin increased with the addition of 10 wt% ADP and increasing the heating temperature. FTIR analysis detected a high water-resistant substance of furan in the adhesives with maltodextrin/ADP ratio 90/10 wt% and heat treatment of 220 °C for 10 min. DSC analysis showed that ADP addition can hasten the reaction of maltodextrin as the endotherm peak temperature was shifted from 272 to 204 °C.