Development of effective coloured flame-retardant finishing for cotton fabric

Abstract

Coloured flame-retardant (FR) dyes are important for applying cotton textile materials. In this study, we have developed flame-retardant coloured cotton fabric (FR@Coloured cotton fabric) using FR-Vat dye. The flame retardant vat dye (FR-Vat dye) was synthesized by the phosphorus group functionalization on active nitrogen and oxygen sites of vat dye, which was further dyed on cotton fabric called FR@Coloured cotton fabric. The synthesized FR@Coloured cotton fabric showed excellent flame retardancy and sustained for 315 s on continuous flame exposure. In contrast, only dyed cotton fabric entirely burned within 18 s. We observed excellent limiting oxygen index (LOI), i.e., 35 % and vertical flammability (char length) value, i.e., 3 cm, for synthesized FR@Coloured cotton fabric. This excellent flame-retardant property provides it an ideal material for practical application and opens a new window for synthesizing coloured flame-retardant fabrics with other dyes and broadens the flame-retardant area for different applications.