Flame retardant and hydrophobic cotton fabrics from intumescent coatings

Intumescent flame retardant and hydrophobic coatings, consisting of sodium montmorillonite (MMT), ammonium dihydrogen phosphate (ADP), and methyltrimethoxysilane (MTMS), were prepared via in situ sol-gel and self-assembly techniques to acquire multifunctional cotton fabrics. The impact of MTMS concentration on hydrophobicity, fire resistance, thermal stability, and heat release behavior of the coated fabrics was investigated. A Si-O-Si network structure was generated via the hydrolysis-condensation reaction of MTMS, induced by the catalysis of ADP. After treated by the coating with 2.0 wt.% of MTMS, the cotton fabric with a total uptake of 22.7 wt.% achieved appreciable flame retardancy and hydrophobicity, as well as satisfactory thermal stability and heat release behaviors. Overall, this research provides a facile and effective approach to prepare flame retardant and hydrophobic cotton fabrics.