Oxidation, Characterization of Leucaena Gum with Sodium Chlorite and its Utilization as Thickener in Textile Printing

摘要

Leucaena gum which is mainly galactomannan was isolated from leucaena seeds and subjected to oxidation using sodium chlorite under variable conditions. Variables investigated were the concentration of the oxidizing agent and the pH of the medium. The products were analysed for acidic and reducing expressed as carboxyl and carbonyl contents, respectively. The rheological properties as well as the utilization of the oxidized products as thickening agents in printing polyester fabric with disperse dye were investigated. The results obtained indicate that both acidic and/or reducing properties increased by increasing the concentration of sodium chlorite. The carboxyl content exhibits the highest value at pH 4. Pastes of the oxidized gum are characterized by a non-Newtonian pseudoplastic behaviour and their apparent viscosity depends on the concentration of the oxidizing agent. Oxidized gum prepared using a concentration ranging from 1-3 g chlorite/100g gum either alone or in admixture with sodium alginate can be used successfully in printing polyester fabrics with disperse dyes.