Superhydrophobic, Abrasion‐Resistant, Thermally Stable Cardanol‐Based <scp>UV</scp> ‐Curable Coatings for Self‐Cleaning, Oil–Water Separation, and Flame‐Retardant/Smoke Suppression Applications

ABSTRACT Petroleum‐based resins face limitations in superhydrophobic and flame‐retardant applications, including high surface energy, poor durability under harsh conditions, low oxygen index, and high heat release. This study employs cardanol, which features a C 15 alkyl chain that confers low surface energy and char formation, along with a phenolic hydroxyl group suitable for graft copolymerization. Two rapidly UV‐curable cardanol‐based coatings were developed. M‐PUA incorporates mesoporous SiO 2 and polydimethylsiloxane into cardanol‐based polyurethane acrylate. At 3 wt% loading of mSiO 2 , it achieves water contact angle (WCA) &gt; 151°, maintains WCA above 144° after 100 abrasion cycles, and exceeds 150° after 24 h immersion in pH = 1 or 13. The coating demonstrates efficient self‐cleaning and oil/water separation, delivering over 98% separation efficiency across 20 cycles for six different oil/water mixtures, with a maximum flux of 2389.86 L m −2 h −1 . The B‐PUA coating constructs a phosphorus‐containing network by grafting di(2‐(methacryloxy)ethyl) phosphate onto cardanol‐Dicyclohexylmethane diisocyanate. It achieves a limiting oxygen index (LOI) of 28 and reduces total heat release by 67.2% and total smoke production by 52.2%. Both coatings exhibit low volatile organic compound emissions and rapid curing, providing an integrated and practical strategy for functionalizing cotton fabrics. These materials show strong potential for self‐cleaning, oil/water separation, and flame‐retardant applications.