New thickening agents for reactive printing of cellulosic fabrics

Four adducts were prepared by polymerizing acrylic acid (AA) in presence of either a pyrodextrin (D) or gum Arabic (GA), and termed as PAA/D₁, PAA/D_2, PAA/GA_1, and PAA/GA₂. These adducts were utilized as thickeners in reactive printing of cotton fabric in comparison with Na‐Alginate. Printing was carried out at different conditions including: NaHCO₃ concentration (0–40 g/K), urea concentration (0–200 g/k), steaming temperature (100–130°C) and time (5–35 min). At optimal NaHCO₃ concentration (30 g/K) the depth of shade of the prints, expressed as K/S values, depended on the nature of the thickener used, and followed the descending order PAA/D₂ > PAA/GA₁ > Na‐Alginate ?PAA/D₁ ≥ PAA/GA₂. Accordingly, PAA/D₁ and PAA/GA₂ were omitted in subsequent trials. Optimal printing conditions were found to be NaHCO₃ concentration (30 g/K), urea concentration (100 g/k), steaming temperature (110°C), and time (15 min). The apparent viscosity of a printing paste, as well as both of K/S value and fastness properties of a print were governed by the nature of the reactive dye and type of thickener. Storing of a printing paste up to 7 days resulted in a decrease in its apparent viscosity along with a slight reduction in K/S value and a little variation in some fastness properties of prints. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 4430–4439, 2006