Evaluation of the leather fatliquoring potential of sulphonated Afzelia africana aril cap oil

Abstract

The synthesis, properties, characterization and sulphonation of Afzelia africana aril cap oil were examined to establish its leather fatliquoring potential. The analysis of the Afzelia africana aril cap oil before and after the completion of sulphonation process was carried out in order to confirm the modification of the oil. The physicochemical properties showed a marked difference between both analyzed oils as the melting point, acid value, free fatty acid, iodine value, saponification value and % SO 3 of the unsulphonated/sulphonated oil were observed to be 6.39 C; 19.90 C, 12.99 mg KOH/g; 0.50 mg KOH/g, 6.50; 5.25, 77 g iodine/100g; 21 g iodine/100g, 185 mg KOH; 176 mg KOH and nil; 3.92 % respectively. The fatliquoring potential was examined and compared with commercial fatliquor using standard methods. A significant improvement in the lubrication and mechanical properties of the leather treated with the sulphonated Afzelia africana aril cap oil was revealed by Sudan stain and Tensile strength; Double edge Tear; Elongation at break test results respectively. The improved lubrication and mechanical properties of the treated leather compared favourably with commercial fatliquor. This study shows that aril caps of A. africana of no commercial value can be a source of fatliquor for the leather industry.

A Fluorescent Tracer Based on Castor Oil for Monitoring the Mass Transfer of Fatliquoring Agent in Leather

“…The chemical shifts between 1.91 and 2.2 ppm showed the protons of the –CH 2 C=O groups. The peak at 3.51 ppm was not observed on the 1 H NMR spectra of natural oils without the hydroxy group, such as rapeseed oil [ 20 ], Afzelia africana aril cap oil [ 3 ] and Sesamum indicum L. seed oil [ 21 ]; thus, it might be the proton of –OH of castor oil. The protons of methylene groups on the glyceride moiety gave δ at 4.01–4.20 ppm, while peaks at 5.15–5.47 ppm were assigned to the protons of CH=CH on the fatty acid chains of castor oil.…”

“…Generally, degreasing is necessary before tanning in order to be beneficial for the penetration and distribution of the tanning agent, from which the natural fats of skins or hides are removed. Without the lubrication of natural fats, the tanned collagen fibers will stick together when the water loss and cracking of wet blue takes place easily [ 3 ]. Therefore, the leather must be fat-liquored using the emulsions of animal fats, vegetable oils, synthetic oils or their derivatives before drying [ 4 , 5 ].…”

The Use of Sulfonated Jatropha curcas Oil for the Processing of Mechanically Improved Leather

“…A similar study on another potential fatliquor, sulfonated Afzelia africana aril cap oil, SACO, recommended for use in the tannery has been carried out [14]. Though not all SACOinduced mechanical properties are better than TRUPON DXV-induced mechanical properties, the results obtained are comparable.…”

“…The reaction of the fatty acids and sulfuric acid for the formation of sulfonated oil was carried out as described by a published procedure [14]. In a conventional reaction, concentrated sulfuric acid (45 ml) was transferred dropwise into a beaker containing 150 g of J. curcas oil (with continuous stirring at 20 °C for 2 h).…”

“…The DSC results showed a substantial rise in the melting point of the oil from 3.18 °C to 14.59 °C on sulfonation. Since the melting point of unsaturated fatty acids is lower than saturated fatty acids [14], it, therefore, means that the substantial rise in melting point revealed by the sulfonated oil is an indication that most of the unsaturated fatty acids in the sulfonated oil were used up during the sulfonation reaction leaving behind saturated fatty acids. The DSC results revealed also that the studied SJCO is thermally stable over a wide temperature range and can be easily used in fatliquoring leather products applicable in diverse climates.…”