ECO-FRIENDLY DYEING TEXTILES WITH NEEM HERB FOR MULTIFUNCTIONAL FABRICS. PART 1: EXTRACTION STANDARDIZATION

Textile industries produce huge amounts of polluted effluents, whereby over 80% of textile dyes are constituted of Benzedrine based dyes or aromatic hazardous substances azo groups that are normally discharged to surface and ground water aquifers. Through the scientific awareness to reach an ecofriendly system, this research part deals on the optimum extraction condition of the new neem natural dye, where the optimization parameters have technical and commercial importance on cost and color yield. This has been carried out using water and different concentrations of water-acetone and water ethanol mixtures at different temperatures, pH values and time intervals. Data observed that the optimum extraction condition was achieved with 50% (v/v) acetone, 18% (w/v) neem amount at pH 9 at 70oC for 60 min where 50% (v/v) wateracetone exhibited 60 % absorbance percentage compared to (31 and 9) % of 40% (v/v) water-ethanol and water respectively. The absorbance values are influenced by the properties of solvents such as, the dipole moment, dielectric constant, and refractive index values. Aqueous extraction gave less amount of pigment and was time consuming, promoting the degradation of color compounds while the other co-solvents increased the extract solubility, giving high extraction capacity. pH 9 increased the diffusion coefficients of color component and the temperature at 70oC for 60 min enhanced the de-aggregation of its molecules. Finally, FTIR analysis investigated the presence of mainly yield quercetin (flavonoid) compounds in neem extract which is known to have antibacterial and antifungal properties giving chance to be applied for antimicrobial textile dyeing in the second part of this study. Key words— Neem, extraction, solvents, natural dyes, environmental technology.