Hydrolysis of leather shavings waste for protein binder

The objective of the research is to treat the leather shaving scrap to reuse it in the leather production as protein binder. The treatment was conducted by hydrolysed the scraps with sodium hydroxide in 90°C with different concentration (1%, 2%, and 3%) and time of hydrolysis (1 hour, 2 hours, and 3 hours). The hydrolysis resulted in two forms of substance, liquid and solid. The liquid substance, which is collagen protein, was then observed for its viscosity, protein content and chrome content. Furthermore, analysis of amino acid was conducted by liquid chromatography-mass spectrometry (LCMS). The result showed that the treatment with 3% sodium hydroxide for 3 hours could produce the best protein binder with 6.64% protein content, 47.55 ppm chrome content, and the viscosity at 16.9 cp. The protein binder contains the amino acid, such as arginine, glycine, aspartic acid, glutamic acid, proline, lysine, and valine. The binder has the potential to replace the common binder, which mainly from casein, used in the leather producers. It is important to know the quality of leather finished by the protein binder. Thus, further study could be explored to apply the binder for various leather finishing applications.