Crockfastness of Polyacrylate Textile Pigment-Printing Binders: Effect of Binder Mechanical Properties and Adhesion to Fabric

The effectiveness of ethyl or butyl acrylate copolymerized with a small proportion of acrylonitrile in improving crockfastness of pigment-printed textile fabrics was determined. Crockfastness was demonstrated to be dependent upon mechanical resistance of the pigmented binder to rubbing and adhesion of the binder to fabric. Crockfastness on cotton fabrics correlated with tensile properties of binder films, ethyl acrylate being superior to butyl acrylate. The correlation failed with polyester fabric because adhesion was a more critical factor, the polyester fiber and yarn surfaces being smoother and more difficult to wet thermodynamically than cotton; in this case, butyl acrylate was superior to ethyl acrylate in adhesion and crockfastness. An analysis of surface free energies showed that better adhesion of the butyl acrylate copolymer to polyester was a consequence of lower total surface energy and lower polarity.