A 'Trojan horse strategy' for the development of a renewable leather tanning agent produced via an AlCl3-catalyzed cellulose depolymerization

TY - JOUR

T1 - A 'Trojan horse strategy' for the development of a renewable leather tanning agent produced via an AlCl3-catalyzed cellulose depolymerization

AU - Jiang, Zhicheng

AU - Ding, Wei

AU - Xu, Shuguang

AU - Remón, Javier

AU - Shi, Bi

AU - Hu, Changwei

AU - Clark, James H.

N1 - © The Royal Society of Chemistry 2020. This is an author-produced version of the published paper. Uploaded in accordance with the publisher’s self-archiving policy. Further copying may not be permitted; contact the publisher for details.

PY - 2020/1/21

Y1 - 2020/1/21

N2 - The development of renewable and non-toxic tanning agents substantially contributes toward the sustainable expansion of the leather industry. Herein, we report a green methodology to synthesize a novel tanning agent consisting of Al-oligosaccharides complexes produced via an efficient AlCl3-catalyzed cellulose depolymerization. Our experimental procedure allowed the production of a high purity tanning agent by the effective removal of the cellulose-decomposed small oxygenates and macromolecular oligosaccharides, via a liquid-liquid extraction using THF as the solvent. This also promoted the decolorization of the leather and enabled the efficient penetration of Al into the collagen matrix of skin. On this matter, experimental work combined with theoretical modeling were used to elucidate the tanning mechanism. In a first step, [Al(OH)1(H2O)4]2+ and [Al(OH)2(H2O)2]+ species weakly interacted or coordinated with the O-1 bond of the oligosaccharides produced. This interaction efficiently prevented the overload of Al species onto the leather surface, thus enhancing their penetration into leather matrix. Then, the active Al species were released from the Al-oligosaccharides complex and strongly coordinated with the -NH2 groups of the collagen fibers present in the leather, which helped to stabilize the fiber bundles, and therefore, contributed to achieve a satisfactory tanning performance.

AB - The development of renewable and non-toxic tanning agents substantially contributes toward the sustainable expansion of the leather industry. Herein, we report a green methodology to synthesize a novel tanning agent consisting of Al-oligosaccharides complexes produced via an efficient AlCl3-catalyzed cellulose depolymerization. Our experimental procedure allowed the production of a high purity tanning agent by the effective removal of the cellulose-decomposed small oxygenates and macromolecular oligosaccharides, via a liquid-liquid extraction using THF as the solvent. This also promoted the decolorization of the leather and enabled the efficient penetration of Al into the collagen matrix of skin. On this matter, experimental work combined with theoretical modeling were used to elucidate the tanning mechanism. In a first step, [Al(OH)1(H2O)4]2+ and [Al(OH)2(H2O)2]+ species weakly interacted or coordinated with the O-1 bond of the oligosaccharides produced. This interaction efficiently prevented the overload of Al species onto the leather surface, thus enhancing their penetration into leather matrix. Then, the active Al species were released from the Al-oligosaccharides complex and strongly coordinated with the -NH2 groups of the collagen fibers present in the leather, which helped to stabilize the fiber bundles, and therefore, contributed to achieve a satisfactory tanning performance.

UR - http://www.scopus.com/inward/record.url?scp=85079066006&partnerID=8YFLogxK

U2 - 10.1039/c9gc03538a

DO - 10.1039/c9gc03538a

M3 - Article

AN - SCOPUS:85079066006

SN - 1463-9262

VL - 22

SP - 316

EP - 321

JO - Green Chemistry

JF - Green Chemistry

IS - 2

ER -