Phytic acid/silica organic-inorganic hybrid sol system: a novel and durable flame retardant approach for wool fabric

The fabrication of long-lasting flame retardant wool textiles through an eco- friendly scheme is still an urgent task. In the present study, an eco-friendly and innovative hybrid silica sol with core-shell structure was prepared by using phytic acid (PA) as catalyst and dopant for tetraethoxysilane. PA/silica organic-inorganic hybrid sol (PA/silica sol) was then employed to produce durable flame retardant wool fabric using a combined nanoparticle adsorption and pad-dry-cure procedure. The treated wool had enhanced thermal stability and greatly suppressed smoke production capacity. It could still be self-extinguishing after 30 washing cycles. The present approach brought no great negative influence on the handle and mechanical performance of wool fabric. The PA/silica sol network was found to participate in the degradation of the treated wool in the solid phase. The formation of highly inflated char during burning also revealed the flame retarding activity of the PA/silica sol on wool by a condensed charring action. (C) 2019 The Authors. Published by Elsevier B.V.