Self-dispersible waterborne comb-like polyester with alkali resistance and pigment-dispersion capability

Waterborne polyester is a common eco-friendly material in which ester bonds are easy to hydrolyze. Therefore, we synthesized a series of waterborne comb-like polyesters (WCPEs) with hydrophilic side chains through aza-Michael addition under green and mild conditions. The physicochemical structure of the polyesters was verified by 1 H NMR, FTIR, and GPC characterizations. The pH value of dispersions dropped by less than 0.7 after storage for 2 months. The dispersions remained stable after 6 months at room temperature. In addition, the WCPEs exhibited good wetting and dispersing ability for pigment particles as Tego 740 W, which is a mature pigment dispersant product for waterborne coatings. Moreover, the cross-linked WCPEs exhibited excellent chemical resistance, there was only 1.2% weight loss, and almost no mechanism properties decline for cross-linked transparent films even after treatment under an alkaline environment for 20 days. Thus, the synthesized WCPE has potential application as an alkali resistance eco-friendly material, and possesses excellent performance as pigment-dispersion resin.