Synthesis of reactive self-adhesive branched polyurethane dispersant for textile pigment printing

Abstract

A series of reactive branched polyurethane dispersants (BPUs) were successfully synthesized based on epoxy as reactive group and nitrogen-containing heterocycles as anchoring group. The branched polyurethane was adopted an ''A2 + B3'' approach with diisocyanate prepolymer and trimethylolpropane. The structure, molecular weight, and thermodynamic property of BPUs were characterized. The pigment dispersions were prepared with BPUs as the dispersant by ball milling, and then the characteristic parameters such as pigment particle size, viscosity, stability, color properties, and fastness were evaluated. Excellent dispersing performances were observed that the particle size of five dispersions were below 200 nm, with the viscosity as low as 6–9 mPa·s. It is worth noting that the pigment dispersion prepared by BPU exhibited excellent stability and self-adhesive performance. These dispersions were printed on cotton fabrics without adhesives, their water washing fastness was approximately grade 4. And the dry rubbing and wet rubbing fastnesses were 3 and 2–3, respectively.