Fluorine‐ and Silicone‐Free Polymer for Smart Textile via Controlled Radical Polymerization and Its Multifunctional Applications

ABSTRACT Superhydrophobic, scratch‐healable, and sustainable coatings hold great promise for preparing smart textiles, particularly by enhancing functionality and durability while minimizing environmental impact. This study reports, for the first time, the development of a three‐arm initiator (COBr 3 ) from castor oil (CO) and its use in reversible complexation‐mediated polymerization (RCMP). A series of homo‐ and co‐polymers, incorporating both petroleum‐derived and bio‐renewable monomers, are synthesized with moderate to high monomer conversions (35%–93%) and low dispersity (1.15–1.49). Specifically, star‐P(SMA 45 ‐ r ‐FMA 22 ) and star‐P(SMA 50 ‐ r ‐FMA 7 ) are synthesized and crosslinked using bis(3‐ethyl‐5‐methyl‐4‐maleimidophenyl)methane (BIM) through the Diels–Alder reaction, and are applied to cellulosic substrates such as cotton cloth (CC), where SMA and FMA refer to stearyl methacrylate and furfuryl methacrylate, respectively. The coated CC demonstrates a water contact angle (WCA) of >150° and sliding at 10°, indicating superhydrophobicity. These coated CC show strong potential for oil–water separation and message encryption in anti‐counterfeiting applications. Additionally, the coatings exhibit thermo‐responsive scratch‐healing behavior at 140°C and possess anti‐staining capabilities. The coating also maintains stability across a wide range of temperatures, chemical environments, and under abrasion. This smart and sustainable textile platform is poised to benefit a range of industries—from oil remediation to functional textiles.