Novel carboxylate comb‐like dispersant used in disperse dyes

Abstract Disperse dyes are insoluble in water, dispersants must be added when dyeing polyester fabrics. Copolymers prepared from styrene (St), acrylic acid (AA), and maleic anhydride (MA) have been used in various fields because of their good amphiphilic properties. In order to obtain a novel dispersant to improve the dispersion property of disperse dyes, St‐AA‐MA copolymer was prepared under certain reaction conditions. Carboxylate comb‐like copolymer(St‐AA‐MA‐PEG) was then synthesized by esterification of St‐AA‐MA with polyethylene glycol (PEG) of different number‐average molecular weights. The structure and properties of St‐AA‐MA and St‐AA‐MA‐PEG were detected and characterized. The effects of length of branch chain and grinding conditions on dispersant properties were also discussed. When PEG600 was used as the branched chain of dispersant, the average particle size of the disperse dye was 256.2 nm, which was smaller than that of the commercial one after grinding. And the zeta potential of the dyestuff using St‐AA‐MA‐PEG600 as dispersant arrived at −41.5 mV. Moreover, the synthesis process of St‐AA‐MA‐PEG is very simple. The resulted sample reveals good dispersion effect for disperse dye. Disperse dye particles featured with small size and concentrated distribution are easy to dye polyester fabrics with suitable dyeing rate. Therefore, St‐AA‐MA‐PEG is an efficient dispersant for disperse dyes.