Fabrication of eco friendly, durable fire retardant and hydrophobic cotton via layer-by-layer assembly

Fabrication of hydrophobic, fireproof and durable coating towards cotton fabrics via a green production and renewable resources has attracted great attention in both academic and industrial fields due to its multifunctional characteristics. Herein, using 1,4-conjugate addition and hydrolysis condensation reaction a polyethyleneimine (PEI) containing hydrophobic surface was constructed onto the biomass cyclodextrin (PEI-CD) simply using ethanol as solution under room temperature. PEI-CD and biomass phytic acid as cationic and anionic solution successfully endowed cotton desirable fire retardancy, hydrophobic and wash durable property via a facile layer-by-layer assembly. The obtained fabrics showed water contact angle up to 137.6 o with significant slowed down wetting rate, the improved limiting oxygen index (28 %), self-extinguish performance and significant delayed ignition time (65 s). Moreover, the treated cotton fabric still showed fire retardancy after 20 wash cycles. The fire retardant mechanism revealed that the condensed phase thermal stable char and gas phase flammable volatiles inhibition simultaneously manifested the high efficient fire retardancy towards cotton. The environmental friendly, facile and multifunctional characteristic of the coating may boost great potentials in the applications of high-performance cotton fabrics.