Synthesis of reactive dye to impart mosquito repellency to nylon

Abstract

Mosquito repellent textile materials are being increasingly in demand as a preventive measure to protect the consumers from mosquito-borne diseases like malaria, dengue, etc. Many of these agents are applied in post-colouration operation to the fabric. Although initially they show good repellency against mosquitoes, upon repeated washing cycles, this effect gets diminished considerably. In the present work, nylon fabric is imparted mosquito repellent finish in one, single operation of dyeing cum finishing. This approach is based on the modification of commonly used mosquito-repellent N,N-diethyl-m-toluamide (DEET) and synthesizing a reactive dye based on this important ingredient. A reactive dye was synthesized in order to impart mosquito repellency to the nylon 6 fabric, DEET was first subjected to nitration using Potassium nitrate and dichloromethane (DCM). This nitrated product was reduced in the presence of water: ethanol (30:70) and the amine, thus, produced was then condensed with 2, 4, 6-trichloro-1, 3, 5-triazine (cyanuric chloride) a reactive group. The resultant product was finally reacted with an amino group present in 6-Amino-2-naphthalenesulphonic acid (Bronner’s acid) to obtain Sodium6-((4-(diethylcarbamoyl)-2-methylphenyl) amino)-1, 3, 5-triazin-2-yl) amino) naphthalene-2-sulfonate (reactive dye). This reactive dye was then applied on nylon 6 fabric by covalent bonding to provide mosquito-repellent material. The chemical structures of the dye were characterized using FTIR and 1H-NMR spectroscopy. The melting point of the dye was characterized by Differential Scanning Calorimetry. The fastness properties of the dyed cum finished fabric were measured to evaluate the performance of the dye. Efficacy of mosquito repellency of the treated nylon 6 fabric was studied using standard methods. The nylon 6 fabric reacted with the mosquito-repellent dye and showed very good durable mosquito-repellent activity.