{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,28]],"date-time":"2026-10-28T22:32:22Z","timestamp":1793226742159,"version":"4.5.0"},"reference-count":126,"publisher":"MDPI AG","issue":"3","license":[{"start":{"date-parts":[[2021,1,29]],"date-time":"2021-01-29T00:00:00Z","timestamp":1611878400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Polymers"],"abstract":"<jats:p>Tanneries generate large amounts of solid and liquid wastes, which contain harmful chemical compounds in the environment, such as chromium, that is used in the tanning process. Until now, they have been almost completely dumped in landfills. Thus, finding eco-sustainable and innovative alternatives for the management and disposal of these wastes is becoming a huge challenge for tanneries and researchers around the world. In particular, the scientific and industrial communities have started using wastes to produce new materials exploiting the characteristics of leather, which are strongly connected with the macromolecular structure of its main component, collagen. None of the reviews on leather waste management actually present in the scientific literature report in detail the use of leather to make composite materials and the mechanical properties of the materials obtained, which are of fundamental importance for an effective industrial exploitation of leather scraps. This comprehensive review reports for the first time the state of the art of the strategies related to the recovery and valorization of both hydrolyzed collagen and leather waste for the realization of composite materials, reporting in detail the properties and the industrial applications of the materials obtained. In the conclusion section, the authors provide practical implications for industry in relation to sustainability and identify research gaps that can guide future authors and industries in their work.<\/jats:p>","DOI":"10.3390\/polym13030429","type":"journal-article","created":{"date-parts":[[2021,1,29]],"date-time":"2021-01-29T09:25:22Z","timestamp":1611912322000},"page":"429","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":80,"title":["Recycling of Chrome-Tanned Leather and Its Utilization as Polymeric Materials and in Polymer-Based Composites: A Review"],"prefix":"10.3390","volume":"13","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-9361-2222","authenticated-orcid":false,"given":"Mariafederica","family":"Parisi","sequence":"first","affiliation":[{"name":"Department of Civil, Chemical, Environmental and Materials Engineering, University of Bologna, 40131 Bologna, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4768-7236","authenticated-orcid":false,"given":"Alessandro","family":"Nanni","sequence":"additional","affiliation":[{"name":"Department of Civil, Chemical, Environmental and Materials Engineering, University of Bologna, 40131 Bologna, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5728-6332","authenticated-orcid":false,"given":"Martino","family":"Colonna","sequence":"additional","affiliation":[{"name":"Department of Civil, Chemical, Environmental and Materials Engineering, University of Bologna, 40131 Bologna, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2021,1,29]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Doble, M., and Kruthiventi, A.K. (2007). Industrial Examples. Green Chemistry and Engineering, Elsevier.","DOI":"10.1016\/B978-012372532-5\/50010-9"},{"key":"ref_2","first-page":"37","article-title":"Marketing Activities in the Leather Industry: Comparative Country Analysis","volume":"1","author":"Sciences","year":"2011","journal-title":"Int. J. Econ. Manag. Sci."},{"key":"ref_3","first-page":"12","article-title":"The Leather Industry: A Chemistry Insight Part I: An Overview of the Industrial Process","volume":"1","author":"Beghetto","year":"2013","journal-title":"Sci. Ca\u2019Foscari"},{"key":"ref_4","unstructured":"Covington, A.D. (2006). The chemistry of tanning materials. Conservation of Leather and Related Materials, Taylor and Francis."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"39","DOI":"10.1016\/j.jclepro.2014.10.017","article-title":"Toxic Hazards of Leather Industry and Technologies to Combat Threat: A Review","volume":"87","author":"Dixit","year":"2015","journal-title":"J. Clean. Prod."},{"key":"ref_6","unstructured":"Germann, H.P. (1999, January 27\u201330). The Ecology of Leather Production\u2013Present State and Development Trends. Proceedings of the XXV IULTCS Congress, Chennai, India."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"11266","DOI":"10.1007\/s11356-014-3055-9","article-title":"A Review on Management of Chrome-Tanned Leather Shavings: A Holistic Paradigm to Combat the Environmental Issues","volume":"21","author":"Pati","year":"2014","journal-title":"Environ. Sci. Pollut. Res."},{"key":"ref_8","first-page":"327","article-title":"Recycling of Leather Waste Containing Chromium\u2014A Review","volume":"5","author":"Ferreira","year":"2011","journal-title":"Mater. Sci. Res. J."},{"key":"ref_9","unstructured":"Roberts, M.T., and Etherington, D. (1982). Bookbinding and the Conservation of Books: A Dictionary of Descriptive Terminology."},{"key":"ref_10","doi-asserted-by":"crossref","unstructured":"Cheema, U., Ananta, M., and Mudera, V. (2011). Collagen: Applications of a Natural Polymer in Regenerative Medicine. Regener. Med. Tissue Eng. Cells Biomater., 287\u2013300.","DOI":"10.5772\/24165"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"929","DOI":"10.1146\/annurev.biochem.77.032207.120833","article-title":"Collagen Structure and Stability","volume":"78","author":"Shoulders","year":"2009","journal-title":"Annu. Rev. Biochem."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"3494","DOI":"10.1074\/jbc.M509333200","article-title":"Collagen XXVIII, a Novel von Willebrand Factor A Domain-Containing Protein with Many Imperfections in the Collagenous Domain","volume":"281","author":"Veit","year":"2006","journal-title":"J. Biol. Chem."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"277","DOI":"10.1126\/science.1138709","article-title":"Analyses of Soft Tissue from Tyrannosaurus Rex Suggest the Presence of Protein","volume":"316","author":"Schweitzer","year":"2007","journal-title":"Science"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"86","DOI":"10.1006\/jsbi.1998.3977","article-title":"Gly-XY Tripeptide Frequencies in Collagen: A Context for Host\u2013Guest Triple-Helical Peptides","volume":"122","author":"Ramshaw","year":"1998","journal-title":"J. Struct. Biol."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"265","DOI":"10.1016\/0020-711X(72)90038-9","article-title":"Relationship between Amino-Acid Composition and Differentiation of Collagen","volume":"3","author":"Toshiharu","year":"1972","journal-title":"Int. J. Biochem."},{"key":"ref_16","unstructured":"Reich, G. (2007). From Collagen to Leather\u2014The Theoretical Background, BASF."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"75","DOI":"10.1126\/science.7695699","article-title":"Crystal and Molecular Structure, of a Collagen-like Peptide at 1.9 \u00c5 Resolution","volume":"266","author":"Bella","year":"1994","journal-title":"Science"},{"key":"ref_18","first-page":"269","article-title":"Thermal Stability of Hide and Leather at Different Moisture Contents","volume":"86","author":"Komanowsky","year":"1993","journal-title":"J. Am. Leather Chem. Assoc."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"2275","DOI":"10.1002\/pc.23140","article-title":"Recycling Leather Waste: Preparing and Studying on the Microstructure, Mechanical, and Rheological Properties of Leather Waste\/Rubber Composite","volume":"36","author":"Santos","year":"2015","journal-title":"Polym. Compos."},{"key":"ref_20","first-page":"47","article-title":"Evidence for the Rupture of Intermolecularly Coordinated Peptide Bonds in the Heat Denaturation (Shrinkage) of Collagen","volume":"41","author":"Gustavson","year":"1946","journal-title":"J. Am. Leather Chem. Assoc."},{"key":"ref_21","first-page":"541","article-title":"Solid Wastes Generation in the Leather Industry and Its Utilization for Cleaner Environment\u2014A Review","volume":"65","author":"Kanagaraj","year":"2006","journal-title":"J. Sci. Ind. Res."},{"key":"ref_22","first-page":"39","article-title":"Beam House and Tanning Operations: Process Chemistry Revisited","volume":"83","author":"Ramasami","year":"1999","journal-title":"J. Soc. Leather Technol. Chem."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"399","DOI":"10.1177\/0734242X16633772","article-title":"The Status and Developments of Leather Solid Waste Treatment: A Mini-Review","volume":"34","author":"Jiang","year":"2016","journal-title":"Waste Manag. Res."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"151","DOI":"10.1007\/s11157-010-9223-6","article-title":"Recovery and Utilization of Proteinous Wastes of Leather Making: A Review","volume":"10","author":"Sundar","year":"2011","journal-title":"Rev. Environ. Sci. Biotechnol."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"39","DOI":"10.1016\/S0304-3894(01)00328-4","article-title":"Chromium Behavior during Thermal Treatment of MSW Fly Ash","volume":"90","author":"Kirk","year":"2002","journal-title":"J. Hazard. Mater."},{"key":"ref_26","first-page":"202","article-title":"The Three Pot Solution for Chromium, Tannins and Solid Wastes: Recovery and Reuse Technique for Spent Semi-Chrome Liquor and Chrome Shavings","volume":"88","author":"Saravanabhavan","year":"2004","journal-title":"J. Soc. Leather Technol. Chem."},{"key":"ref_27","first-page":"365","article-title":"Biochemical Method for Extraction and Reuse of Protein and Chromium from Chrome Leather Shavings: A Waste to Wealth Approach","volume":"108","author":"Pati","year":"2013","journal-title":"J. Am. Leather Chem. Assoc."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"155","DOI":"10.1080\/10408440500534032","article-title":"Toxicity and Carcinogenicity of Chromium Compounds in Humans","volume":"36","author":"Costa","year":"2006","journal-title":"Crit. Rev. Toxicol."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"514","DOI":"10.1016\/j.jhazmat.2008.03.070","article-title":"Leather Waste\u2014Potential Threat to Human Health, and a New Technology of Its Treatment","volume":"160","author":"Kolomaznik","year":"2008","journal-title":"J. Hazard. Mater."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"222","DOI":"10.1021\/es00001a029","article-title":"Chemical Kinetic Mechanism for Atmospheric Chromium","volume":"29","author":"Christian","year":"1995","journal-title":"Environ. Sci. Technol."},{"key":"ref_31","unstructured":"Houghton, J.T. (2001). Climate Change 2001: The Scientific Basis, The Press Syndacate of the University of Cambridge."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"436","DOI":"10.1016\/j.resconrec.2006.05.006","article-title":"Conversion of Leather Wastes to Useful Products","volume":"49","author":"Kantarli","year":"2007","journal-title":"Resour. Conserv. Recycl."},{"key":"ref_33","first-page":"192","article-title":"Potential Uses of Tanned Collagen","volume":"76","author":"Lollar","year":"1981","journal-title":"J. Am. Leather Chem. Assoc."},{"key":"ref_34","first-page":"187","article-title":"Products of Enzymic Decomposition of Chrome-Tanned Leather Waste","volume":"83","author":"Langmaier","year":"1999","journal-title":"J. Soc. Leather Technol. Chem."},{"key":"ref_35","first-page":"63","article-title":"Utilizzazione Della Rasatura Nella Concia Al Cromo","volume":"69","author":"Manzo","year":"1993","journal-title":"Cuoio Pelli Mat. Conci."},{"key":"ref_36","unstructured":"Wojciech, L., Miesczyslzw, G., and Ursula, M. (1998). Leather Treatment to Remove Chromium. (1998003685A1), WO."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"1091","DOI":"10.1016\/j.wasman.2009.12.006","article-title":"Finished Leather Waste Chromium Acid Extraction and Anaerobic Biodegradation of the Products","volume":"30","author":"Ferreira","year":"2010","journal-title":"Waste Manag."},{"key":"ref_38","first-page":"46","article-title":"Characterization of Low-Molecular Weight Collagen Hydrolysates Prepared by Combination of Enzymatic and Acid Hydrolysis","volume":"104","author":"Kolomaznik","year":"2009","journal-title":"J. Am. Leather Chem. Assoc."},{"key":"ref_39","first-page":"328","article-title":"Upgrading Leather and Felt Scrap into Proteins","volume":"78","author":"Bataille","year":"1983","journal-title":"J. Am. Leather Chem. Assoc."},{"key":"ref_40","unstructured":"Ferreira, M.J., Pinto, V.V., Rodrigues, J., Pinho, S., Azevedo, M., and Almeida, M.F. (2014, January 3\u20136). Advanced and Clean Technologies for Chromium Tanned Leather Waste Recycling and Green Energy Production. Proceedings of the 15th Romanian Textiles and Leather Conference, Poiana Bra\u0219ov, Romania."},{"key":"ref_41","first-page":"45","article-title":"Utilisation of Leather Waste\u2014Animal Feedstuff from Chrome Shavings: Part 1 Pilot Plant Study","volume":"75","author":"Reis","year":"1991","journal-title":"J. Soc. Leather Technol. Chem."},{"key":"ref_42","unstructured":"Zhang, X., Yang, D., GaO, Q., and Liu, H. (2001). Process for Extracting Protein from Waste Leather. (1313352A), CN."},{"key":"ref_43","first-page":"528","article-title":"Possibilita Reali Di Recupero Dei Sottoprodoti Dell\u2019industria Conciaria","volume":"64","author":"Simoncini","year":"1988","journal-title":"Cuoio Pelli Mat. Conci."},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"835","DOI":"10.1016\/S0956-053X(03)00040-0","article-title":"Towards Zero Discharge of Chromium-Containing Leather Waste through Improved Alkali Hydrolysis","volume":"23","author":"Mu","year":"2003","journal-title":"Waste Manag."},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"1329","DOI":"10.3844\/ajassp.2008.1329.1335","article-title":"Effect of the Detoxification on the Shrinkage Temperature and PH of Chromium Leather Waste, Another Promising Way for the Tannery Pollution","volume":"5","author":"Malek","year":"2008","journal-title":"Am. J. Appl. Sci."},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"156","DOI":"10.1016\/j.jhazmat.2009.04.118","article-title":"New Approach of Depollution of Solid Chromium Leather Waste by the Use of Organic Chelates: Economical and Environmental Impacts","volume":"170","author":"Malek","year":"2009","journal-title":"J. Hazard. Mater."},{"key":"ref_47","first-page":"56","article-title":"Enzyme Hydrolysis of Solid Tannery Wastes: Solid State Enzyme Production","volume":"82","author":"Chakraborty","year":"1998","journal-title":"J. Soc. Leather Technol. Chem."},{"key":"ref_48","first-page":"103","article-title":"Optimization of Hydrolysis of Chrome Shavings by Enzyme from p. Lilacinus","volume":"99","author":"Chakraborty","year":"2004","journal-title":"J. Am. Leather Chem. Assoc."},{"key":"ref_49","first-page":"264","article-title":"Enzymic Treatment of Chrome Shavings","volume":"85","author":"Taylor","year":"1991","journal-title":"J. Am. Leather Chem. Assoc."},{"key":"ref_50","unstructured":"Taylor, M.M., Diefendorf, E.J., Na, G.C., and Marmer, W.N. (1992). Enzymatic Processing of Materials Containing Chromium and Protein. (5094946A), US."},{"key":"ref_51","first-page":"199","article-title":"Efficiency of Enzymic Solubilization of Chrome Shavings as Influenced by Choice of Alkalinity-Inducing Agents","volume":"86","author":"Taylor","year":"1991","journal-title":"J. Am. Leather Chem. Assoc."},{"key":"ref_52","unstructured":"Taylor, M.M., Diefendorf, E.J., and Marmer, W.N. (1991, January 23). Compendium of Advanced Topics on Leather Technology. Proceedings of the XXI Congress of the International Union of Leather Technologists and Chemists Societies, Barcelona, Spain."},{"key":"ref_53","first-page":"380","article-title":"Characterization of Products Isolated by Enzyme Treatment of Chromium-Containing Leather Waste","volume":"87","author":"Taylor","year":"1994","journal-title":"J. Am. Leather Chem. Assoc."},{"key":"ref_54","doi-asserted-by":"crossref","first-page":"211","DOI":"10.1016\/S0956-053X(98)00032-4","article-title":"Original Contributions\u2014Processing of Leather Waste: Pilot Scale Studies on Chrome Shavings. Isolation of Potentially Valuable Protein Products and Chromium","volume":"18","author":"Cabeza","year":"1998","journal-title":"Waste Manag."},{"key":"ref_55","first-page":"299","article-title":"Process Simulation and Cost Estimation of Treatment of Chromium-Containing Leather Waste","volume":"10","author":"Cabeza","year":"1998","journal-title":"J. Am. Leather Chem. Assoc."},{"key":"ref_56","doi-asserted-by":"crossref","unstructured":"Taylor, M.M., Diefendorf, E.J., Thompson, C.J., Brown, E.M., and Marmer, W.N. (1994). Extraction and Characterization of \u201cChrome-Free\u201d Protein from Chromium-Containing Collagenous Waste Generated in the Leather Industry, ACS Publications.","DOI":"10.1021\/bk-1994-0575.ch012"},{"key":"ref_57","unstructured":"Cabeza, L.F., Taylor, M.M., DiMaio, G.L., Brown, E.L., Marmer, W.N., Carrio, R., Celma, P.J., and Cot, J. (1999, January 27\u201330). Cost Effective Processing of Leather Waste: Pilot Scale Studies on Chrome Shavings from Cattle Hides and Sheep Skins Isolation of Potentially Valuable Protein Products and Utilization of Recovered Chromium. Proceedings of the XXV IULTCS Congress India (Chennai) Waste Manage Technol, Chennai, India."},{"key":"ref_58","unstructured":"Taylor, M.M., Diefendorf, E.J., Marmer, W.N., and Brown, E.M. (1993). Enzymatic Processing of Materials Containing Chromium and Protein. (5271912A), U.S. Patent."},{"key":"ref_59","unstructured":"Cioca, G., and Fertell, P.A. (1982). Manufactured Article Based on Leather and a Polyisocyanate. (2495054A1), FR."},{"key":"ref_60","first-page":"83","article-title":"Development of a Tanning Process Based on Using Hydrolyzated Material Collected from Leather Scrap","volume":"97","author":"Munoz","year":"2002","journal-title":"J. Am. Leather Chem. Assoc."},{"key":"ref_61","doi-asserted-by":"crossref","first-page":"52","DOI":"10.1016\/j.tca.2008.01.003","article-title":"Plasticizing Collagen Hydrolysate with Glycerol and Low-Molecular Weight Poly (Ethylene Glycols)","volume":"469","author":"Langmaier","year":"2008","journal-title":"Thermochim. Acta"},{"key":"ref_62","first-page":"55","article-title":"Modifyining Products of Enzymatic Breakdown of Chrome-Tanned Leather Wastes with Glutaraldehyde","volume":"87","author":"Langmaier","year":"2003","journal-title":"J. Soc. Leather Technol. Chem."},{"key":"ref_63","first-page":"28","article-title":"Computer-Assisted Method to Measure the Adhesive Properties of Hydrolysis Products from Collagen","volume":"92","author":"Taylor","year":"1998","journal-title":"J. Am. Leather Chem. Assoc."},{"key":"ref_64","doi-asserted-by":"crossref","first-page":"101","DOI":"10.1016\/j.ijadhadh.2004.04.004","article-title":"Curing Urea\u2013Formaldehyde Adhesives with Hydrolysates of Chrome-Tanned Leather Waste from Leather Production","volume":"25","author":"Langmaier","year":"2005","journal-title":"Int. J. Adhes. Adhes."},{"key":"ref_65","first-page":"171","article-title":"Chemical modification of protein products isolated from chromium-containing solid tannery waste and resultant influence on physical and functional pro perties","volume":"94","author":"Taylor","year":"1999","journal-title":"J. Am. Leather Chem. Assoc."},{"key":"ref_66","doi-asserted-by":"crossref","unstructured":"Taylor, M.M., Diefendorf, E.J., Thompson, C.J., Brown, E.M., and Marner, W.N. (1994). Extraction and Characterization of \u201cChrome-Free\u201d Protein from Chromium-Containing Collagenous Waste Generated in the Leather Industry. Polymer from Agricultural Coproducts, American Chemical Society. Chapter 12.","DOI":"10.1021\/bk-1994-0575.ch012"},{"key":"ref_67","doi-asserted-by":"crossref","first-page":"47","DOI":"10.1515\/tsd-2002-390112","article-title":"Hydrolysates of Chromed Waste as Raw Materials for the Production of Surfactants","volume":"39","author":"Langmaier","year":"2002","journal-title":"Tenside Surfactants Deterg."},{"key":"ref_68","doi-asserted-by":"crossref","first-page":"31","DOI":"10.1515\/tsd-2002-390209","article-title":"Degradation of Chromed Leather Waste Hydrolysates for the Production of Surfactants","volume":"39","author":"Langmaier","year":"2002","journal-title":"Tenside Surfactants Deterg."},{"key":"ref_69","doi-asserted-by":"crossref","first-page":"479","DOI":"10.1023\/A:1008763900729","article-title":"Biocompatibility of Modified Silica-Protein Composite Layers","volume":"19","author":"Brasack","year":"2000","journal-title":"J. Sol Gel Sci. Technol."},{"key":"ref_70","doi-asserted-by":"crossref","first-page":"237","DOI":"10.1016\/j.desal.2012.10.025","article-title":"Study on Scale Inhibition Performances and Interaction Mechanism of Modified Collagen","volume":"309","author":"Qiang","year":"2013","journal-title":"Desalination"},{"key":"ref_71","doi-asserted-by":"crossref","first-page":"347","DOI":"10.1007\/s12649-010-9030-x","article-title":"Preparation and Characterization of Composite Sheets from Collagenous and Chromium\u2013Collagen Complex Wastes Using Polyvinylpyrrolidone: Two Problems, One Solution","volume":"1","author":"Ashokkumar","year":"2010","journal-title":"Waste Biom. Valorization"},{"key":"ref_72","first-page":"182","article-title":"Potential Applications for Gelatin Isolated from Chromium-Containing Solid Tannery Waste: Microencapsulation","volume":"94","author":"Cabeza","year":"1999","journal-title":"J. Am. Leather Chem. Assoc."},{"key":"ref_73","first-page":"232","article-title":"Utilization of Chromium-Tanned Leather Solid Wastes in Microencapsulation","volume":"106","author":"Ocak","year":"2011","journal-title":"J. Am. Leather Chem. Assoc."},{"key":"ref_74","doi-asserted-by":"crossref","first-page":"857","DOI":"10.1007\/s10973-005-7458-1","article-title":"Cross-Linking Epoxide Resins with Hydrolysates of Chrome-Tanned Leather Waste","volume":"88","author":"Langmaier","year":"2007","journal-title":"J. Therm. Anal. Calorim."},{"key":"ref_75","first-page":"225","article-title":"Enzymatic Modification of Hydrolysis Products from Collagen Using a Microbial Transglutaminase. II. Preparation of Films","volume":"97","author":"Taylor","year":"2002","journal-title":"J. Am. Leather Chem. Assoc."},{"key":"ref_76","first-page":"435","article-title":"Enzymatic Modification of Hydrolysis Products from Collagen Using a Microbial Transglutaminase. III. Preparation of Films with Improved Mechanical Properties","volume":"98","author":"Taylor","year":"2003","journal-title":"J. Am. Leather Chem. Assoc."},{"key":"ref_77","doi-asserted-by":"crossref","first-page":"866","DOI":"10.1111\/j.1365-2621.1994.tb08146.x","article-title":"Strength of Protein Gels Prepared with Microbial Transglutaminase as Related to Reaction Conditions","volume":"59","author":"Sakamoto","year":"1994","journal-title":"J. Food Sci."},{"key":"ref_78","doi-asserted-by":"crossref","first-page":"806","DOI":"10.1021\/bm015519h","article-title":"Gelatin-Based Blends and Composites. Morphological and Thermal Mechanical Characterization","volume":"2","author":"Chiellini","year":"2001","journal-title":"Biomacromolecules"},{"key":"ref_79","first-page":"143","article-title":"Application of Protein Hydrolysate from Chrome Shavings for Polyvinyl Alcohol-Based Biodegradable Material","volume":"97","author":"Kupec","year":"2002","journal-title":"J. Am. Leather Chem. Assoc."},{"key":"ref_80","first-page":"108","article-title":"Thermal Properties of Hydrolysates of Chrome-Tanned Leather Scraps","volume":"49","author":"Mokrejs","year":"2007","journal-title":"Indian Chem. Eng."},{"key":"ref_81","first-page":"100","article-title":"Gel-Sol Transitions of Chrome Tanned Leather Waste Hydrolysate","volume":"85","author":"Langmaier","year":"2001","journal-title":"J. Soc. Leather Technol. Chem."},{"key":"ref_82","unstructured":"Castiello, D., Chiellini, E., Cinelli, P., Corti, A., D\u2019Antone, S., Puccini, M., Salvadori, M., and Vitolo, S. (2007, January 20\u201324). Polyethylene-Collagen Hydrolizate Thermoplastic Blends: A New Reutilization Route to Transform a Waste of the Leather Industry into Environmentally Degradable Plastics. Proceedings of the XXIX Congress of the International Union of Leather Technologists and Chemists Societies, Washington, DC, USA."},{"key":"ref_83","first-page":"29","article-title":"Modification of Chrome Tanned Leather Waste Hydrolysate with Epichlorhydrin","volume":"90","author":"Langmaier","year":"2006","journal-title":"J. Soc. Leather Technol. Chem."},{"key":"ref_84","first-page":"81","article-title":"Cross-Linking Phosphoric Acid Hydrolysates of Collagen with Cyanuric Chloride","volume":"92","author":"Chakarska","year":"2008","journal-title":"J. Soc. Leather Technol. Chem."},{"key":"ref_85","doi-asserted-by":"crossref","first-page":"323","DOI":"10.1007\/s12649-011-9072-8","article-title":"Hybrid Biodegradable Films from Collagenous Wastes and Natural Polymers for Biomedical Applications","volume":"2","author":"Murali","year":"2011","journal-title":"Waste Biom. Valorization"},{"key":"ref_86","first-page":"315","article-title":"Development of Regenerated Protein Fibers from a Collagen-Polyvinyl Alcohol Complex","volume":"102","author":"Shin","year":"2007","journal-title":"J. Am. Leather Chem. Assoc."},{"key":"ref_87","doi-asserted-by":"crossref","first-page":"616","DOI":"10.1002\/jbm.a.31858","article-title":"Surface Engineering of PHBV by Covalent Collagen Immobilization to Improve Cell Compatibility","volume":"88","author":"Wang","year":"2009","journal-title":"J. Biomed. Mater. Res. Part A"},{"key":"ref_88","doi-asserted-by":"crossref","first-page":"2775","DOI":"10.1002\/bit.24937","article-title":"Electrospun Aligned PHBV\/Collagen Nanofibers as Substrates for Nerve Tissue Engineering","volume":"110","author":"Prabhakaran","year":"2013","journal-title":"Biotechnol. Bioeng."},{"key":"ref_89","doi-asserted-by":"crossref","first-page":"1253","DOI":"10.1016\/j.biomaterials.2004.04.031","article-title":"Cartilage Tissue Engineering PLLA Scaffold with Surface Immobilized Collagen and Basic Fibroblast Growth Factor","volume":"26","author":"Ma","year":"2005","journal-title":"Biomaterials"},{"key":"ref_90","doi-asserted-by":"crossref","first-page":"489","DOI":"10.1002\/jbm.a.30386","article-title":"Collagen-Carbon Nanotube Composite Materials as Scaffolds in Tissue Engineering","volume":"74","author":"MacDonald","year":"2005","journal-title":"J. Biomed. Mater. Res. Part A"},{"key":"ref_91","first-page":"234","article-title":"Studies on the Generation of Biogas from Collagen Hydrolysate Obtained from Chrome Shavings by Alkaline Hydrolysis: A Greener Disposal Method","volume":"2","author":"Pati","year":"2013","journal-title":"Res. J. Recent Sci."},{"key":"ref_92","first-page":"15","article-title":"Utilisation of Hide Wastes for the Production of High-Protein Feed Meals on the Basis of a \u2019collagen Amino-Acid Index\u2019","volume":"71","author":"Zuchowski","year":"1987","journal-title":"J. Soc. Leather Technol. Chem."},{"key":"ref_93","first-page":"55","article-title":"Experience in Industrial Practice of Enzymatic Dechromation of Chrome Shavings","volume":"95","author":"Kolomaznik","year":"2000","journal-title":"J. Am. Leather Chem. Assoc."},{"key":"ref_94","first-page":"91","article-title":"Hydrolysis of Tannery Wastes to Protein Meal for Animal Feedstuffs: A Process and Product Evaluation","volume":"59","author":"Montoneri","year":"1994","journal-title":"J. Chem. Technol. Biotechnol. Int. Res. Process. Environ. Clean Technol."},{"key":"ref_95","first-page":"119","article-title":"Automatic Control of Recycling Technology for Chromium from Liquid and Solid Tannery Waste","volume":"100","author":"Kolomaznik","year":"2005","journal-title":"J. Am. Leather Chem. Assoc."},{"key":"ref_96","first-page":"83","article-title":"Processing of Leather Waste: Pilot Scale Studies on Chrome Shavings. Part II. Purification of Chrome Cake and Tanning Trials","volume":"93","author":"Cabeza","year":"1998","journal-title":"J. Am. Leather Chem. Assoc."},{"key":"ref_97","doi-asserted-by":"crossref","first-page":"1372","DOI":"10.1021\/es015635s","article-title":"Green Route for the Utilization of Chrome Shavings (Chromium-Containing Solid Waste) in Tanning Industry","volume":"36","author":"Rao","year":"2002","journal-title":"Environ. Sci. Technol."},{"key":"ref_98","first-page":"46","article-title":"Recovery and Reuse of Chromium from Leather Shavings: Formation of Chromium-Containing Ceramic Pigments","volume":"96","author":"Berry","year":"2001","journal-title":"J. Am. Leather Chem. Assoc."},{"key":"ref_99","first-page":"1","article-title":"Processing of Chrome-Tanned Solid Waste Generated in the Leather Industry: Recovery of Proteins and Synthesis of a Pigment for Paint","volume":"99","author":"Azzi","year":"2001","journal-title":"J. Am. Leather Chem. Assoc."},{"key":"ref_100","first-page":"217","article-title":"Preparation of Chrome Liquor Using Chrome Shavings as Reducing Agent","volume":"100","author":"Cheng","year":"2005","journal-title":"J. Am. Leather Chem. Assoc."},{"key":"ref_101","first-page":"170","article-title":"Tanning Studies with Basic Chromium Sulfate Prepared Using Chrome Shavings as a Reductant: A Call for\u2019wealth from Waste\u2019approach to the Tanning Industry","volume":"77","author":"Rao","year":"2004","journal-title":"J. Am. Leather Chem. Assoc."},{"key":"ref_102","first-page":"223","article-title":"Leather Powder as an Agent for Removing Environmentally Hazardous Organic Compounds","volume":"87","author":"Przepiorkowska","year":"2003","journal-title":"J. Soc. Leather Technol. Chem."},{"key":"ref_103","doi-asserted-by":"crossref","first-page":"280","DOI":"10.1016\/j.jhazmat.2007.11.001","article-title":"Removal of As (V) and Cr (VI) from Aqueous Solutions Using Solid Waste from Leather Industry","volume":"151","author":"Oliveira","year":"2008","journal-title":"J. Hazard. Mater."},{"key":"ref_104","doi-asserted-by":"crossref","first-page":"49","DOI":"10.1002\/pc.10411","article-title":"Production of Leather-like Composites Using Chemically Modified Short Leather Fibers. I: Chemical Modification by Emulsion Polymerization","volume":"23","year":"2002","journal-title":"Polym. Compos."},{"key":"ref_105","doi-asserted-by":"crossref","first-page":"327","DOI":"10.1177\/0892705713518794","article-title":"Reuse of Leather Shavings as a Reinforcing Filler for Poly (Vinyl Alcohol)","volume":"29","author":"Liu","year":"2016","journal-title":"J. Thermoplast. Compos. Mater."},{"key":"ref_106","doi-asserted-by":"crossref","first-page":"546","DOI":"10.1590\/1516-1439.318114","article-title":"Particles of Coffee Wastes as Reinforcement in Polyhydroxybutyrate (PHB) Based Composites","volume":"18","author":"Reis","year":"2015","journal-title":"Mater. Res."},{"key":"ref_107","doi-asserted-by":"crossref","first-page":"109381","DOI":"10.1016\/j.polymdegradstab.2020.109381","article-title":"Wine Derived Additives as Poly (Butylene Succinate)(PBS) Natural Stabilizers for Different Degradative Environments","volume":"182","author":"Nanni","year":"2020","journal-title":"Polym. Degrad. Stab."},{"key":"ref_108","doi-asserted-by":"crossref","first-page":"49713","DOI":"10.1002\/app.49713","article-title":"Effect of the Wine Wastes on the Thermal Stability, Mechanical Properties, and Biodegradation\u2019s Rate of Poly (3-hydroxybutyrate)","volume":"138","author":"Nanni","year":"2020","journal-title":"J. Appl. Polym. Sci."},{"key":"ref_109","doi-asserted-by":"crossref","first-page":"501471","DOI":"10.1155\/2015\/501471","article-title":"Rice Husk Filled Polymer Composites","volume":"2015","author":"Arjmandi","year":"2015","journal-title":"Int. J. Polym. Sci."},{"key":"ref_110","doi-asserted-by":"crossref","first-page":"1099","DOI":"10.1007\/s10924-016-0891-3","article-title":"Polylactic Acid (PLA) Biocomposites Filled with Waste Leather Buff (WLB)","volume":"25","author":"Ambone","year":"2017","journal-title":"J. Polym. Environ."},{"key":"ref_111","doi-asserted-by":"crossref","first-page":"586","DOI":"10.1007\/s12204-012-1329-2","article-title":"Preparation and Characterization of the Covalent-Integrated Poly(Lactic Acid) and Scrap Leather Fiber Composites","volume":"17","author":"Duan","year":"2012","journal-title":"J. Shanghai Jiaotong Univ."},{"key":"ref_112","unstructured":"Donati, F., Puccini, V., and Vitolo, S. (2019). Procedimento Di Produzione Di Materiale Similpelle e Materiale Cos\u00ec Ottenuto. (3536830A1), EP."},{"key":"ref_113","unstructured":"Moses, A.J., Babu, A.S., and Kumar, S.A. (2015, January 20\u201321). Fabrication and Characterization of Leather Waste and LDPE\/LLDPE Blend Composites Fabrication and Characterization of Leather Waste and LDPE\/LLDPE Blend Composites. Proceedings of the International Conference on Advances in Production and Industrial Engineering, Tiruchirappalli, India."},{"key":"ref_114","doi-asserted-by":"crossref","first-page":"807","DOI":"10.1016\/j.compositesb.2007.10.005","article-title":"Dimensional Stability and Mechanical Behaviour of Wood-Plastic Composites Based on Recycled and Virgin High-Density Polyethylene (HDPE)","volume":"39","author":"Adhikary","year":"2008","journal-title":"Compos. Part B Eng."},{"key":"ref_115","doi-asserted-by":"crossref","first-page":"72","DOI":"10.1106\/69D3-L9GT-2YEM-R43C","article-title":"Plasticized Poly(Vinyl Chloride) Filled with Waste Leather Particles","volume":"33","author":"Babanas","year":"2001","journal-title":"J. Elastomers Plast."},{"key":"ref_116","doi-asserted-by":"crossref","first-page":"17","DOI":"10.4186\/ej.2013.17.3.17","article-title":"An Approach to Utilize Crust Leather Scrapes, Dumped into the Land, for the Production of Environmental Friendly Leather Composite","volume":"17","author":"Nahar","year":"2013","journal-title":"Eng. J."},{"key":"ref_117","doi-asserted-by":"crossref","first-page":"181","DOI":"10.1007\/s12221-015-0181-z","article-title":"Leather Fibres as Reinforcement for Epoxy Composites: A Novel Perspective","volume":"16","author":"Senthil","year":"2015","journal-title":"Fibers Polym."},{"key":"ref_118","doi-asserted-by":"crossref","first-page":"175","DOI":"10.1007\/s10924-016-0930-0","article-title":"Leather Insole with Acupressure Effect: New Perspectives","volume":"26","author":"Senthil","year":"2018","journal-title":"J. Polym. Environ."},{"key":"ref_119","first-page":"102","article-title":"Natural Rubber-Leather Composites","volume":"15","author":"Natchimuthu","year":"2013","journal-title":"Pol\u00edm. Ci\u00eanc. Tecnol."},{"key":"ref_120","doi-asserted-by":"crossref","first-page":"P105","DOI":"10.22376\/ijpbs.2016.7.4.p105-110","article-title":"Physico-Chemical Properties of Reconstituted Fibers Composite Prepared from Leather Waste","volume":"7","author":"Sumathi","year":"2016","journal-title":"Int. J. Pharma Bio Sci."},{"key":"ref_121","doi-asserted-by":"crossref","first-page":"979","DOI":"10.1002\/app.33692","article-title":"Recycling of Chrome-tanned Leather Waste in Acrylonitrile Butadiene Rubber","volume":"121","author":"Mohamed","year":"2011","journal-title":"J. Appl. Polym. Sci."},{"key":"ref_122","doi-asserted-by":"crossref","first-page":"2801","DOI":"10.1177\/0021998310369597","article-title":"The Effect of Leather Fibers on the Properties of Rubber-Leather Composites","volume":"44","author":"Ferreira","year":"2010","journal-title":"J. Compos. Mater."},{"key":"ref_123","doi-asserted-by":"crossref","first-page":"89","DOI":"10.1177\/147776061803400202","article-title":"Investigating Effect of Chrome Tanned Leather Scraps in Ethylene Propylene Diene Monomer Rubber","volume":"34","year":"2018","journal-title":"Prog. Rubber Plast. Recycl. Technol."},{"key":"ref_124","doi-asserted-by":"crossref","first-page":"33","DOI":"10.1016\/j.saa.2011.09.052","article-title":"Optical and Spectroscopic Studies on Tannery Wastes as a Possible Source of Organic Semiconductors","volume":"86","author":"Nashy","year":"2012","journal-title":"Spectrochim. Acta Part A Mol. Biomol. Spectrosc."},{"key":"ref_125","doi-asserted-by":"crossref","first-page":"574","DOI":"10.1016\/j.conbuildmat.2007.10.024","article-title":"Incorporation of Chromium-Tanned Leather Residue to Asphalt Micro-Surface Layer","volume":"23","author":"Krummenauer","year":"2009","journal-title":"Constr. Build. Mater."},{"key":"ref_126","doi-asserted-by":"crossref","unstructured":"Z\u0103inescu, G., Deselnicu, V., and Constantinescu, R. (2018, January 18\u201320). Composite Structures Containing Leather Fibers with Applications in Constructions Industry. Proceedings of the ICAMS 2018\u20137th International Conference on Advanced Materials and Systemshttps, Bucharest, Romania.","DOI":"10.24264\/icams-2018.XI.9"}],"container-title":["Polymers"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2073-4360\/13\/3\/429\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T05:17:08Z","timestamp":1760159828000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2073-4360\/13\/3\/429"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2021,1,29]]},"references-count":126,"journal-issue":{"issue":"3","published-online":{"date-parts":[[2021,2]]}},"alternative-id":["polym13030429"],"URL":"https:\/\/doi.org\/10.3390\/polym13030429","relation":{},"ISSN":["2073-4360"],"issn-type":[{"value":"2073-4360","type":"electronic"}],"subject":[],"published":{"date-parts":[[2021,1,29]]}}}