Durable Flame-Resistant and Ultra-Hydrophobic Aramid Fabrics via Plasma-Induced Graft Polymerization

A durable flame-resistant and ultra-hydrophobic phosphorus–fluoride coating on aramid fabrics was achieved by plasma-induced graft polymerization. The aramid fabrics were activated and roughed through the low-pressure plasma firstly, which involves the sequential coating of a mixture of phosphorus–fluoride emulsion copolymer. When potentially exposed to flame or water, such a surface produces a dual effect in which it is intumescent and waterproof, successfully giving the coated fabrics flame-resistant ultra-hydrophobic bifunctional properties. Thus, adhesive coatings provide a convenient way to resolve the issue of washing durability of the coatings. The as-prepared fabrics last for 10 repeatable washing cycles without losing their flame resistance and superhydrophobicity, suggesting future applications as advanced multifunctional textiles. Compared to an untreated coating, its char length was less than 1 cm with no measurable after-flame or after-glow times, and its static water contact angle remained stable above 170°. Meanwhile, the control sample was unable to extinguish the fire with a damage length of 10.6 cm and a water contact angle of 100°. All the results indicate that plasma-reactive polar groups interact between phosphorus and fluorine elements, leading to an increased relative atom ratio P and F through Energy-Dispersive Spectrometer (EDS) spectra and XPS analysis, which inhibits the flammability and wettability.