Melamine-Based Polymeric Crosslinker for Cleaner Leather Production

Abstract

To augment sustainable tanning, less chrome input, high functional quality leather processed via no restricted substance in processing, and ease to treat the inevitable protein waste generated are the key challenge, and currently, they have become the active part of leather research. Our work covers the synthesis of a formaldehyde-free chromium-incorporated polymeric tanning agent (FF-CIPTA) and its application in a reformed leather processing route which ensures near zero discharge of chromium containing solid waste. The preliminary characterization of FF-CIPTA reveals that the developed product is stable up to pH 5.2, and the particle size distribution ranges from 955 to 1450 nm with 12% Cr2O3 content. The present work significantly reduces the tanning agent input without compromising the thermal stability (103 °C) of the leather because of its multicrosslinking nature. Since the product exhibits a polymeric character, it provides tanning-cum-filling action which in turn reduces the retanning agent consumption in subsequent processes. Scanning electron microscopic study, porosity analysis, and hand assessment results clearly indicate the significant improvement in organoleptic properties. In addition, the process also enjoys the benefits of zero chromium containing solid waste generation, 71.4% reduction in chromium input, and high chromium transfer efficiency (92%) than the conventional process (36%), and 74.4% reduction in total dissolved solids generation. Furthermore, the water consumption and chemical input are reduced by 51.6 and 17%, respectively. Reduction in wastewater treatment cost and a high economic value of chromium-free leather scraps leads to a cumulative gain of US$ 39.84 per ton of raw material processing. Overall, a potential and practical applicability for cleaner and sustainable tanning is well established.

Synthesis, characterization, and functionalization of superadhesive melamine formaldehyde polyvinylpyrrolidone resins doped with metallic and graphene oxide nanoparticles for better industrial applications

“…The shows an electronic cloud shift contrary to dopant and others which tries to attach. Also, the CN at 1551.24 cm −1 infers the oscillations due to the different electronic environments of the C atom as well as of the N atoms 77,78 . Their bonding atoms and electron density both shift the electron cloud along with the activities of electrons.…”

“…Also, the C N at 1551.24 cm À1 infers the oscillations due to the different electronic environments of the C atom as well as of the N atoms. 77,78 Their bonding atoms and electron density both shift the electron cloud along with the activities of π electrons. This seems to be a reason that the MFPR acts as a superadhesive on the surface of the solid including the glassy, metallic, nonmetallic, and soft surfaces.…”

Win–Win Approach Toward Chrome-Free and Chrome-Less Tanning with Waterborne Epoxy Polymers: A Sustainable Way To Curb the Use of Chrome

“…Finding a means to prevent or reduce the usage of minerals in tanning is required because the standard tanning procedure uses them. 1,5 To lessen the amount of chromium in the system, vegetable tanning, glutaraldehyde, phosphonium (THPS), melamine resins, oxazolidines, and hyperbranched polymers have been used with conventional chrome tanning. The high hydrothermal/shrinkage temperatures and negative formaldehyde testing are absent during tanning without chromium.…”

“…The majority of these requests come from the car industry and related businesses. Finding a means to prevent or reduce the usage of minerals in tanning is required because the standard tanning procedure uses them. , …”

Sustainable metal-free leather manufacture via synergistic effects of triazine derivative and vegetable tannins

“…[1]. However, conventional chrome tanning generates substantial non-renewable chrome-containing wastewater [2] and solid wastes [3,4]. These unfixed Cr(III) in leather and wastewater may be oxidized to carcinogenic Cr(VI) [5,6], which seriously threatens human health and environment.…”