Flame-retardant cotton fabric through graft copolymerisation

In an attempt to impart flame-retarding properties to the cotton fabric, post-grafting phosphorylation reactions on grafted cotton fabric were carried out. Photochemical graft copolymerisation of 4-vinyl pyridine (4-VP) onto cotton fabric using benzophenone as photosensitiser was carried out. Maximum percentage of grafting Pg, ( 18.50 %) was obtained under optimum conditions; irradiation time 75 min, 0.5 ml of benzophenone, [4-VP]=748.71 x 10(-2) mole/l and 5 ml of water in the reaction mixture. Aliphatic alcohols of varying chain length decreased percentage of grafting. The pendant pyridine rings of the 4-VP grafted cotton fabric were converted to pyridinium chloride followed by the reaction with acrylamide to give 2-amido-ethylpyridiniumchloride. This was subjected to phosphorylation reaction with PCl3/petroleum ether. The phosphorylated grafted cotton fabric burns only in the presence of flame with very slow propagation of the flame (only 3.8 cm(2)) was found to burn of the total area of 147 cm(2) with 0. 12 g of the ash content. Characterisation of gray cotton fabric and modified cotton fabric was carried out by FTIR., thermogravimetric analysis, crease recovery, and moisture absorption studies.