Performance of Flame Retardant Wool Fabric Grafted with Vinyl Phosphate

In this paper, a flame retardant dimethyl-2–(methacryloyloxyethyl) phosphate (DMMEP) was applied to wool fabrics by the graft copolymerization technique initiated with potassium persulfate (KPS) in water media. FTIR and SEM testing were used to explore the grafting evidence on the fiber surface, the SEM results show chemical deposition on the wool fiber surface and the scales could not be seen clearly. FTIR testing exhibited IR absorption of DMMEP on the wool fiber. Thermal gravimetric analysis, differential thermal analysis (DTA), and char residue morphology SEM observation show the decomposition mode of wool fabrics and infer the possible flame retardant mechanism. The phosphorus based flame retardant DMMEP was prone to promote more nonflammble char during combustion, and increased add-on of DMMEP produced increased fabric char. With a DMMEP add-on increase from 50% to 100% on the weight of wool fabric, the treated wool fabric demonstrated high flame retardancy with an LOI above 35% which means it can not be ignited with a candle like fire, and could pass the vertical flammability test. DMMEP treatment slightly affected whiteness and moisture regain, but yielded a relatively large decrease in permeability and tensile strength, which should be explored further in later research.