Dyeing of cotton fabric for improved mosquito repellency

Recently, mosquito repellent textile materials are increasingly in demand from consumers as a preventive measure from mosquito-borne diseases like malaria, dengue. Mosquito repellent-treated textile material initially shows good repellency against mosquitoes but upon repeated washing cycles this effect gets washed off considerably. In the present work, 4-Amino-N, N-diethyl-3-methyl benzamide (MD) is synthesized from N, N-diethyl-m-toluamide (DEET) and it is used as base material for synthesis of azo group. This synthesized base MD was then coupled with three different napthols to get dyed cotton fabric using diazotization process. This dyed cotton fabric has imparted mosquito repellent finish in one, single operation of dyeing cum finishing. This approach is based on modification of universally used mosquito repellent and synthesizing an azo group-based dye in the fibre matrix of the cotton fabric. The chemical structures of the MD were characterized using FT-IR and H-1-NMR spectroscopy. The fastness properties of the dyed cum finished fabric were measured to evaluate the performance of the dyed fabric. Efficacy of mosquito repellency of the dyed cotton fabric was studied using standard methods. The dyed cotton fabric using napthols and MD showed very good and durable mosquito-repellent activity.