Application of gelatin extracted from chrome shavings for the glazed finishing of leather

The objective of this work was to ascertain the performance of extracted gelatin from dechromed leather shavings as a coating in the finishing of leather. Gelatin is a protein-based material isolated from chrome-tanned collagenic wastes. A comparison between a commercial protein-based product, extracted gelatin and a mixture of extracted gelatin/glycerol was carried out. Based on the results obtained in previous studies, two fixing agents were used to fix the finishing: 5-ethyl-1-aza-3, 7-dioxabicyclo [3,3,0] octane (oxazolidine II) and ethylene glycol diglycidyl ether (EGDE). The mixture gelatin/glycerol (using glycerol as a plasticiser) presented satisfactory results, compared with the commercial product, for the abrasion, gloss and flex resistance, although a poor performance under wet rub fastness (assessment of 1 on the grey scale (ISO 105-A02, A03) and adhesion tests were found due to the hygroscopic nature of glycerol. The formulation for potential further studies was the extracted gelatin fixed with EGDE, which showed the best performance on dry rub fastness (4-5 on the grey scale) and finish adhesion, and a good performance on resistance to abrasion and to flex (low loss of finishing and no cracking observed). The results confirmed the potential for gelatin, obtained from chrome shavings, to be used as a leather finishing agent