Surface Modification of Non-Ionic Polyester Fabric into an Anionic Platform for Low Temperature Cationic Basic Dyeing with Improved Colorfastness Properties

This research work involves surface anionization of non-ionic polyester (PET- polyethylene terephthalate) fabric through a novel and facile modification technique to facilitate cationic dyeing, particularly basic dyeing under normal atmospheric conditions, instead of traditional sophisticated non-ionic disperse dyeing. Initially, the modification of PET with differently prepared modifiers was performed at 50 degrees C which introduced an anionic carboxylate group (COO-) on its surface to promote effective bond formation with cationic basic dyes. The modification process did not alter the inherent mechanical properties, i.e., strength and elongation of the PET fabric. Subsequently, the basic dyeing of the sample was carried out at a lower temperature (50-60 degrees C) for 60 min. The dyeing of the modified PET fabric with modifier 1 at 60 degrees C yielded the best output for the basic blue 2GL dye in terms of color properties and shade quality. For modifier 2, the color output after dyeing at 50 degrees C was off shade and only a reddish tone appeared, but the color strength (K/S) and the evenness of the shade were satisfactory. Both modifiers significantly improved the color fastness properties of the dyed fabric in the range of very good (4) to excellent (4/5) fastness rating, while the unmodified fabric had a comparatively lower fastness grade (3).