Preparation and characterization of guaran carbamate as a thickener in disperse dye printing pastes

Abstract

Guaran gum has been isolated from guar seeds and subjected to chemical modification via carbamation using different concentrations of urea. The guaran carbamate samples were analyzed for nitrogen. The results show that the maximum nitrogen content is obtained on using 8g urea/20g guaran gum at 150°C for 30 min and further increases in urea concentration is accompanied by a decrease in the nitrogen content. The printing pastes of these derivatives are characterized by a nonNewtonian pseudoplastic behaviour and their apparent viscosity decreases with the increase in nitrogen content. The utilization of guaran carbamate, either alone or in a mixture with a synthetic thickener Carbopol, in printing polyester fabrics with disperse dyes has also been studied. It is observed that the <i>K/S </i>values and fastness properties of the samples treated with guaran derivatives are nearly comparable with those of the samples printed using Carbopol alone.