Abstract:
Polyacrylamide/guar gum (PAam/GG) adduct was prepared by polymerization of a highly concentrated solution of acrylamide (Aam) in the presence of guar gum (GG) by using ammonium persulfate initiator. The adduct was used as a thickener for reactive printing of wool and nylon-6 under different conditions, including thickening agent type and concentration, urea concentration, benzyl alcohol concentration, steaming temperature and time, dye type, and fixation method. Data revealed, under the conditions examined, that (1) for a given set of printing conditions, K/S value is higher in PAam/GG than that in GG, regardless of substrate used; (2) increasing urea concentration, in the printing paste (up to 160 g/kg in wool, or up to 120 g/kg in nylon-6) or benzyl alcohol concentration up to 160 g/kg (in both substrates) was accompanied by a significant increase in depth of shade regardless of thickener used; (3) raising steaming temperature from 100degreesC to 130degreesC resulted in enhancing the depth of shade; (4) prolonging steaming time, at 120degreesC, from 10 to 30 min resulted in improving the depth of shade; (5) the depth of shade depends on the type of dye used and is higher in wool than in nylon-6 and in steaming than in thermosoling; (6) the flow properties of printing pastes based on PAam/GG or GG are of the thixotropic type, and the apparent viscosity, at the same shear rate, is higher in PAam/GG than that in GG; and (7) the apparent viscosity of printing pastes increased by storing up to 10 days.
