Synthesis of comb-like polycarboxylate dispersants and the effect of anchoring groups on the dispersion performance and stability for disperse dyes

To obtain a new type of amphiphilic dispersant for improving the dispersion performance of disperse dyes, a series of polycarboxylate sodium salt dispersants (MHT, MAT, MST, MLT) with different anchoring groups were prepared by polymerization with one of hydroxyethyl acrylate, acrylamide, sodium p-styrenesulfonate, and sodium allylsulfonate, using maleic anhydride as the main carboxylic acid monomer, and isoprenyl alcohol ethoxylate as solventized side chain. The effect of the ratio of hydrophilic to hydrophobic groups on the performance of the dispersants was also discussed to understand the molecular composition of the macromolecular polycarboxylate dispersants with polyether as the side chain and the effect of this ratio on the dispersion of hydrophobic dyes. When hydroxyethyl acrylate was used as the hydrophobic monomer and the molar ratio of hydrophilic to hydrophobic groups was 2:1, the average particle size of the dispersed dye solution was 292.9 nm, smaller than that of the milled commercially available dye. The zeta potential of the dye using MHT-4 as a dispersant reached −36.7 mV. Furthermore, the synthesis process of MHT-4 was straightforward, and the prepared dye solution demonstrated that the dispersed dye particles were characterized by small particle size, centralized distribution, and stability, making it easy to dye polyester fabrics with a suitable dyeing rate. Therefore, MHT-4 is an efficient dispersant suitable for dyeing with disperse dyes.