A review of the green chemistry approaches to leather tanning in imparting sustainable leather manufacturing

Hassan, Mohammad Mahbubul; Harris, Jane; Busfield, James J. C.; Bilotti, Emiliano

doi:10.1039/d3gc02948d

Cited by 20 publications

(8 citation statements)

References 153 publications

(302 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In a conventional metal-free tanning system, varieties of single or combinations tanning system are available like THPS, glutaraldehyde and veg-based combination systems, sulfone-based syntan, and tanning agent. 1 The drawbacks of the present system are identified to be huge requirements of post tanning chemicals to improve its properties matches with the chrome tanned leather. In particular, the major limitations associated with the conventional wet white system are that leathers have poor strength characteristics and hence need heavy retanning for their final performance and also strong fatliquoring becomes mandatory to attain the desired level of softness.…”

Section: ■ Introductionmentioning

confidence: 96%

“…There is a growing demand for eco-benign collagen stabilization/tanning systems owing to stringent environmental regulations of metal based tanning system. In a conventional metal-free tanning system, varieties of single or combinations tanning system are available like THPS, glutaraldehyde and veg-based combination systems, sulfone-based syntan, and tanning agent . The drawbacks of the present system are identified to be huge requirements of post tanning chemicals to improve its properties matches with the chrome tanned leather.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Biocompatible Thermally Responsive Vinyl Sulfone Silica Nanocapsules as Stabilizing and Softening Agents for Metal-Free Leather Production

Meganathan,

Sundararajan,

Javid

et al. 2024

ACS Appl. Nano Mater.

View full text Add to dashboard Cite

Developing nanomaterial-based leather chemicals with multifunctional smart properties and biocompatibility for crafting high-quality leather products poses a significant challenge. The double layer formation of silica with an amine and vinyl sulfone terminal created metal-free robust oil deliverable silica nanocapsules (Si−O and Si-OVS). The hydroamination of vinyl sulfone and amine terminal silica yielded a distinctive flower-like structure within a core−shell model. This model encompasses a silica−oil core surrounded by a silica shell incorporating vinyl sulfone. This intricate synthesis results in the encapsulation of a larger quantity of oil, making it suitable to serve as a softening agent for leather applications. Two silica capsule types were developed: one with low oil content and amine terminals for collagen stabilization and another with high oil content and vinyl sulfone terminals for lubrication. The efficacy of Si−O nanocapsules as a stabilization agent and Si-OVS as a softening agent has been demonstrated through their application in leather processing, revealing noteworthy improvements over conventional organic (conventional silica tanning) and metal-based tanning agents. The leather treated with Si−O and Si-OVS exhibits enhanced tensile strength, tear resistance, and softness. This enhancement is attributed to the formation of chemical bonds between the vinyl sulfone terminals and the amine and carboxyl groups present in collagen fibers instead of conventional electrostatic interactions. Additionally, the cytotoxicity of Si−O and Si-OVS were evaluated, revealing no toxicity toward a fibroblast cell line and confirming the biocompatible nature of the prepared nanocapsules. The multifunctional oil-deliverable silica nanocapsules address the challenges of a metal-free tanning process, enabling the smart delivery of oil into the three-dimensional leather matrix, thereby contributing to the production of high-quality leather.

show abstract

Section: ■ Introductionmentioning

confidence: 96%

Section: Introductionmentioning

confidence: 99%

Biocompatible Thermally Responsive Vinyl Sulfone Silica Nanocapsules as Stabilizing and Softening Agents for Metal-Free Leather Production

Meganathan,

Sundararajan,

Javid

et al. 2024

ACS Appl. Nano Mater.

View full text Add to dashboard Cite

show abstract

“…11 Ecological leather manufacturing development will thus become the trend of the times. 12 At present, chrome-free tanning agents mainly include two categories, i.e., chrome-free metal tanning agents 13−15 and organic tanning agents, 16−18 there are also some synthetic tanning agents in the organic category, such as TWS, F-90, aromatic synthetic tanning agent, 19 amino resin tanning agent, 20 acrylic resin tanning agent, 21 epoxy compound tanning agent, 22−24 etc., which are mainly combined with the active groups on leather collagen by covalent, ionic, or hydrogen bonds to achieve the tanning effect through their aldehyde, amino, carboxyl, and other functional groups. In recent years, there has been a growing recognition of the potential of TWS, F-90, and organic phosphine tanning agents to replace traditional chrome tanning agents.…”

Section: Introductionmentioning

confidence: 99%

“…On such a basis, a variety of documents have been introduced worldwide to limit the chromium content in wastewater, suggesting the essential role of developing new types of chrome-free tanning agent to replace chrome tanning agent in the sustainable development strategy of leather . Ecological leather manufacturing development will thus become the trend of the times . At present, chrome-free tanning agents mainly include two categories, i.e., chrome-free metal tanning agents − and organic tanning agents, − in which tannin extract is the most commonly used.…”

Section: Introductionmentioning

confidence: 99%

β-Cyclodextrin-Based Chrome-Free Tanning Agent Results in the Sustainable and Cleaner Production of Eco-Leather

Dang,

Qiu,

et al. 2024

ACS Sustainable Chem. Eng.

View full text Add to dashboard Cite

This study aimed to pioneer the development of an innovative, ecofriendly, and chrome-free tanning agent, with a focus on promoting sustainable practices in ecological leather production. Two novel biomass-derived tanning agents, namely, β-TCD and β-GCD, were synthesized through a one-pot grafting process involving environmentally friendly epoxy monomers: triglycidyl isocyanurate (TGIC) and glycerol triglycidyl ether (GTE). Characterization through various analytical methods, including FTIR, 1 H NMR, XPS, GPC, SEM, and TGA, confirmed the successful grafting of TGIC and GTE onto β-cyclodextrin (β-CD) backbones. The resulting β-TCD and β-GCD exhibited notable epoxide values of 0.349 and 0.388 mol/100 g, respectively, along with a broader molecular weight distribution of intermediates. These newly developed tanning agents, β-TCD and β-GCD, were then applied in depickling goatskin tanning experiments. Results indicated that the crust leather tanned with β-TCD and β-GCD displayed favorable thermal stability, with shrinkage temperatures reaching 84 and 82 °C, respectively. Moreover, the thickening rates of the leather exceeded 40%. The crust leathers tanned with β-TCD, and β-GCD demonstrated excellent physical and mechanical properties, as well as notable resistance to yellowing compared to conventional commercial chrome-free tanning agents like TWS and F-90. Overall, this research emphasizes the efficacy of natural cyclodextrin materials as potent and environmentally friendly alternatives to chromium-based tanning agents, showcasing their significant potential in advancing sustainable and cleaner practices in leather production.

show abstract

“…36 The main objective of this work, improving the stability of WPI-based aerogels in aqueous environments, was accomplished by tannin-assisted phase separation and gelation, drying with supercritical CO 2 and followed by gas-phase silanization of the resulting aerogels. Tannins were chosen for reducing the hydrophilicity of WPI aerogels, via a process mimicking leather tanning, 37 the most important chemical process that converts animal skin into leather by stabilizing the collagen fibers. Both types of tannins (hydrolyzable and condensed) were used in this work, and the reactions were carried out in neutral or alkaline solutions.…”

Section: Introductionmentioning

confidence: 99%

Whey Protein Isolate-Based Aerogels with Improved Hydration Properties for Food Packaging Applications

Effraimopoulou,

Kalmár,

Paul

et al. 2024

ACS Appl. Nano Mater.

View full text Add to dashboard Cite

In the present work, tannin-modified whey protein isolate (WPI/tannin) aerogels were synthesized, and their hydration properties were evaluated. The materials were prepared by introducing two different tannins (one hydrolyzable and one condensed) in the protein matrix via thermal-induced gelation of neutral or alkaline aqueous solutions (pH 7, 9, or 11) at 80 °C. WPI and WPI/tannin aerogels are nanostructured porous materials with high BET surface areas (216−353 m 2 g −1 ). Subsequently, WPI and WPI/tannin aerogels were hydrophobized via silanization (with bis(trimethylsilyl)amine) in the gas phase (HWPI and HWPI/tannin aerogels). As a result of silanization, BET surface areas were reduced to 87−242 m 2 g −1 . The hydration properties of all aerogels were studied by measuring the water uptake and water contact angles. Pristine WPI aerogels absorbed high amounts of water (up to 4794% w/w in 24 h), swelled, and eventually disintegrated. WPI/tannin aerogels prepared with the condensed tannin absorbed more water (219−559% w/w) than those prepared with the hydrolyzable tannin (81−88% w/w). In any case, the water uptake was significantly lower compared with that of pristine WPI aerogels. After silanization, all aerogels absorbed much smaller amounts of water (39−84% w/w). The reduced water uptake was in agreement with the water contact angles, which were in the ranges 35−55°for WPI aerogels, 40−60°for WPI/tannin aerogels, 80−86°for HWPI aerogels, and 100−116°for HWPI/tannin aerogels. These results clearly indicate that both the introduction of tannin in the protein matrix and the silanization of the solid network are necessary to obtain water-stable WPI-based aerogels. There is an immense need for replacing the existing plastic-based food packaging with biobased and biodegradable materials. In this context, our results address the major disadvantage of most biobased materials (i.e., poor stability in aqueous environments) and render these new aerogels good candidates for food packaging applications.

show abstract

A review of the green chemistry approaches to leather tanning in imparting sustainable leather manufacturing

Abstract: Leather is an important biobased collagen protein material, which is used in the manufacture of a variety of products including footwear, automotive upholstery, garments, and sports equipment. Animal skins/hides are...

Cited by 20 publications

References 153 publications

Biocompatible Thermally Responsive Vinyl Sulfone Silica Nanocapsules as Stabilizing and Softening Agents for Metal-Free Leather Production

Biocompatible Thermally Responsive Vinyl Sulfone Silica Nanocapsules as Stabilizing and Softening Agents for Metal-Free Leather Production

β-Cyclodextrin-Based Chrome-Free Tanning Agent Results in the Sustainable and Cleaner Production of Eco-Leather

Whey Protein Isolate-Based Aerogels with Improved Hydration Properties for Food Packaging Applications

Contact Info

Product

Resources

About