Advanced masking agent for leather tanning from stepwise degradation and oxidation of cellulose

Abstract

An oligosaccharide-based masking agent suitable for chrome-free metal tanning was produced from cellulose via a stepwise degradation and oxidation process. Firstly, an AlCl3-NaCl-H2O/γ-valerolactone (GVL) biphasic solvent system was established for...

A salt-free pickling and chrome-free tanning technology: a sustainable approach for cleaner leather manufacturing

“…Specifically, the tanning of leather could be attributed to the dispersion and fixation of collagen fibers through an abundant number of crosslinking networks between the tanning agent and the –NH 2 /–COOH groups in the collagen matrix. 46 This was similar to the combination of chrome-free organic tanning agents with amino groups of collagen fibers. This resulted in the reduction of positive charges on the crust leather 47 and lowering of the isoelectric point compared to that of the chrome-tanned leather.…”

Biomass derived oligosaccharides for potential leather tanning

“…On the other side, the water-soluble Al-oligosaccharides complex could be used as an environmentally friendly tanning agent without separating the catalyst or products. Combining with H 2 O 2 oxidation, the distribution of the oxygen-containing groups was adjusted; assisted by extracting the noncarbohydrate products using an organic solvent, part of the undesirable and colored byproducts were removed [12]. These techniques further improved the tanning performance of the complex tanning agents.…”

Biomass-derived aldehyde tanning agents with in situ dyeing properties: a ‘Two Birds with One Stone’ strategy for engineering chrome-free and dye-free colored leather

“…However, in recent years, impacted by the environmental pollution issues from leather making, the global leather industry is facing severe challenges, among which chrome pollution is a key bottleneck restricting the ecological development of the leather industry. [1][2][3] Currently, chrome tanning is the most widely used technique for leather tannage as it can endow leather with excellent thermal stability and organoleptic properties by forming robust coordination crosslinking structures in the leather matrix. In fact, in addition to the coordination crosslinking formed via metal tanning, covalent crosslinking formed via organic tanning can also endow leather with stable tanning properties.…”