Preparation of sepiolite-based hybrid silica sol and its application in polyester/cotton fabric flame retardant finishing

Abstract

Halogen-free flame-retardant finishing of textiles is of great significance. In this study, a new type of phosphorus-rich organic-inorganic flame-retardant hybrid silica sol was prepared by the ion replacement reaction between natural sepiolite and biomass phytic acid, which was then used as the flame retardant for coating finishing of polyester/cotton (T/C) fabric. The structure and morphology of the hybrid silica sol was investigated. The results indicated that prepared silica sol maintained the fibrous structure of sepiolite, which would be helpful to reduce the damage to the mechanical properties of T/C fabric in the flame-retardant finishing process. The tests on the flame retardancy and mechanical properties of T/C fabrics show that the flame retardancy and mechanical properties of T/C fabrics coated by sepiolite-based silica sol were improved. Compared with raw T/C fabric, the limit oxygen index of the optimal sample increased by 24.8% and the char length decreased by 76%. In addition, the elongation at break at warp direction of the optimal sample was 16.3%, which was about 39.16% higher than that of raw T/C fabric. The hybrid sepiolite-based silica sol has broad application prospect.