Durable Flame‐Retarding and Antifouling Cotton Fabrics Based on Hydrophobic Protection Coating

Durability of flame retardant of ammonium polyphosphate (APP) on cotton fabrics is often compromised due to its inherent hydrophilicity and low adhesion. This water‐soluble APP is easy to wash off especially when exposure to wet and polluted environments. Intense interaction and stable hydrophobicity are the key strategy to improve its flame‐retardant durability. Therefore, in this study, coating composites with polyfluoroacrylate (C 6 F) and APP were synthesized, exhibiting both good flame retardancy and hydrophobicity. With just 0.2 wt% C 6 F and 4.5 wt% APP, water contact angle of this coated cotton fabric reaches 138.3°, and limiting oxygen index value is increased to 29.5% with self‐extinguishing behavior meeting B1 rating standard. Additionally, due to low surface energy of C 6 F, more fluorine elements distribute on the coating surface, demonstrating excellent antifouling properties to many domestic pollutants like coffee, milk, cola, ink, and sand. Significantly, stability and durability of flame retardancy are successfully achieved owing to hydrogen bonding and charge interaction between C 6 F, APP, and fabric substrate. Accordingly, it could maintain its weight gain rate, hydrophobicity and flame retardancy after 10 times water rinse. This proposes a facile and effective strategy to prolong the service life of flame‐retardant cotton fabrics even under polluted conditions.