Synthesis of sulfonated Sesamum indicum L. seed oil and its application as a fatliquor in leather processing

Abstract: Fatliquor is an oil-in-water emulsion that improves the physical properties of leather such as tensile strength, flexibility, and softness by lubricating the leather fibres. Sulfonated Sesamum indicum oil was synthesized, characterized, and examined for consideration as a substitute for imported fatliquor in Nigeria. The sulfonation of the oil was confirmed by the significant observations made in the FTIR, 1H NMR, 13C NMR, and 13C NMR DEPT analysis results. A remarkable difference was observed in the physicochemical properties results of both unsulfonated and sulfonated oils. The sulfonated sesame fatliquor was applied onto goatskin and compared with a commercial sulfated fatliquor in the processing of shoe upper leather using standard methods. The average results for tensile strength, double edge tear, elongation, and softness results for the commercial and synthesized fatliquors are as follows: 14.27 N/mm2; 13.77 N/mm2, 50.61 N; 60.11 N, 38.06%; 54.28%, 25.2; 25.0. A comparable level of lubrication of the leather treated with the sulfonated Sesamum indicum oil and that treated with the commercial leather fatliquor was revealed by the Sudan IV stain test as well as scanning electron microscopy analysis results. Experimental analyses, therefore, show that the as-synthesized sulfonated Sesamum indicum oil could be considered as a substitute for imported fatliquor in the leather industry. Graphical abstract: [Figure not available: see fulltext.]. © 2021, The Author(s).