Synthetic Oligomers with Urea Binding and their Role as Crosslinkers in Improving the Printing Quality on Cotton Fabric

Urea as a dye stabilizer, swelling, and disaggregation agents is a key role in silk printing of cotton fabric. Nonetheless, applications of urea cause environmental problems due to the high ammonia nitrogen emission. The oligomer containing urea linkage has been produced by heating the mixture of urea and sulfamic acid in melt state at 140–150 °C. The printing paste was prepared using urea and the urea-linkage oligomers (ULO) in different concentrations (10, 15, 20, and 25 ml) and applied to the cotton fabric, the print quality was studied, respectively. The color strength of the printed fabrics was evaluated in term of CIE Lab values. The wash and abrasion fastness were indicated according to the known standard. The print quality that enhanced sharpness was compared with microscopic images. The presence of OH and NH 2 active functional groups at both ends of urea oligomers has provided suitable conditions for crosslinking with the binder and has been confirmed to improve the quality of wash and abrasion stability which are the main features of the printed fabrics. According to the results, the hue and chroma of the printed fabrics in the presence of urea oligomers were considerably improved in contrast to the samples printed with the paste containing urea. Moreover, the urea-linkage addition could dramatically increase the sharpness and cleanness of the printed fabrics via key effect on the rheological properties of the printing paste. The printed fabric in the presence of 20 g of urea oligomers had the best printing quality. In general, the application of the ULO as a urea’s replacement can reduce the environmental problems and leading to the green process.