Toward a universal polymeric dispersant for diverse pigment systems in surface coatings via azole anchoring modification

Abstract Dispersants play a vital role in stabilizing pigment dispersions in the surface coating industry. This study addresses the growing need for versatile, high‐performance additives by advancing the development of a polymeric dispersant, PD‐1, originally designed with carboxyl anchoring groups from fatty acid. While PD‐1 demonstrated effectiveness with titanium dioxide pigments, its limited compatibility with other pigments hindered broader application. To overcome this limitation, we developed PD‐A1, a modified dispersant featuring an azole anchoring group grafted through amidation of the PD‐1 carboxyl group using 1‐(3‐aminopropyl) imidazole. The structural modification was confirmed via FTIR and 1 H‐NMR spectroscopy. PD‐A1's performance was evaluated with four diverse pigments and it consistently achieved lower viscosity, enhanced stability, and improved compatibility across all pigment systems. Nitrocellulose coatings prepared with PD‐A1‐based dispersions exhibited superior optical and mechanical properties, including enhanced gloss, transparency, jetness, tinting strength, and favorable rub‐out performance. Thermogravimetric analysis (TGA) and Fourier transform infrared spectroscopy (FTIR) analysis confirmed the effective adsorption of PD‐A1 on various pigment surfaces, underscoring the efficacy of the azole group as a universal anchoring site. This advancement represents a significant step toward developing a universal dispersant, capable of addressing the diverse requirements of the surface coating industry while aligning with the industry's shift toward sustainable and bio‐based solutions. Highlights Dispersant incorporated with fatty acid modified for wider pigment compatibility. Grafting of azole anchoring group enhances dispersant efficiency in a wider system. Improved viscosity and stability in pigment dispersion with modified dispersant. Pigmented nitrocellulose coatings recorded improved gloss and tinting strength.