Factors affecting the radiation grafting of diethylaminoethyl methacrylate onto cotton, polyester and polyamide fabrics

Factors affecting the radiation grafting of diethylaminoethyl methacrylate (DEAEMA) onto cotton, polyester and polyamide fabrics have been studied to obtain optimum conditions that improve the dyeability of Drimalan reactive dye. It is observed that gamma doses of up to 4 Mrad (40 kGy) do not show any noticeable graft yield until benzoyl peroxide catalyst is added. All the fabrics show maximum graft yield at 0.01% benzoyl peroxide, 10% monomer(DEAEMA) and 1:15 fabric-to-liquor ratio. A dose of 2 Mrad has been used in all the grafting experiments to avoid fabric degradation. Induction period or dose is observed before the start of the grafting process. The induction period is the shortest for cotton (0.2 Mrad corresponding to 0.56 h irradiation) while that for polyamide fabric it is 0.7 Mrad (7 kGy) which corresponds to about 2 h irradiation. The graft yield is considerably higher for the natural cotton fabric than those for the synthetic polyester and polyamide fabrics. The dyeability of the fabrics with Drimalan dye improves considerably as the graft yield increases up to 7% with no further appreciable changes for higher degrees of grafting. The pH of the dyebath affects the dyeability of the fabrics giving an optimum condition at a pH value of 3 for 2% grafted fabrics.