Orientador: Jorge Akutsu / Banca: Jorge Hamada / Banca: Bernardo Arantes do Nascimento Teixeira / Resumo: A "serragem cromada" é um tipo de resíduo sólido gerado em grandes quantidades nas indústrias de processamento de couro e nos curtumes do Brasil. Do ponto de vista ambiental é um resíduo considerado muito problemático, pois o mesmo se enquadra segundo a legislação brasileira na classe dos resíduos perigosos, devido à presença de concentrações lixiviáveis relativamente altas do elemento cromo trivalente utilizado no processo de curtimento. O destino da "serragem cromada" vinha tendo de maneira quase que generalizada seu simples lançamento em "lixões" sem nenhum tipo de controle. Mais recentemente, em função de pressões por parte dos órgãos de controle ambiental às indústrias de processamento de couro e curtumes, a "serragem cromada", vem sendo estocada nas mesmas, constituíndo enormes pilhas de armazenamento nos pátios dessas indústrias. Mediante o exposto, a presente pesquisa... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The "tanned leather waste" is a type of solid waste generated in great amounts in tanneries and industries of leather processing in Brazil. From tehe environmental point of view it is considered to be a very problematic waste, since its classification is "hazardous waste", according to the Brazilian rules, due to the presence of relatively high lixiviable concentrations of the element trivalent chromium used in the tanning process. "The tanned leather waste" destination tended to be the simple dropping on rubbish landfills without any type of control. More recently, due to pressures of the environmental control organs on the industries of leather processing and tanneries, "the tanned leather waste" has been stored inside the manufacturing facilities, becoming enormous strorage piles in those industries courtyards. By the exposed, this research proposes an appropriate way to the destination for... (Complete abstract click electronic access below) / Mestre

Made available in DSpace on 2014-06-11T19:24:47Z (GMT). No. of bitstreams: 0 Previous issue date: 2002-12-16Bitstream added on 2014-06-13T20:13:04Z : No. of bitstreams: 1 fujikawa_es_me_bauru.pdf: 1484999 bytes, checksum: 31162ce2d13e3ce701a178ab751b5312 (MD5) / A serragem cromada é um tipo de resíduo sólido gerado em grandes quantidades nas indústrias de processamento de couro e nos curtumes do Brasil. Do ponto de vista ambiental é um resíduo considerado muito problemático, pois o mesmo se enquadra segundo a legislação brasileira na classe dos resíduos perigosos, devido à presença de concentrações lixiviáveis relativamente altas do elemento cromo trivalente utilizado no processo de curtimento. O destino da serragem cromada vinha tendo de maneira quase que generalizada seu simples lançamento em lixões sem nenhum tipo de controle. Mais recentemente, em função de pressões por parte dos órgãos de controle ambiental às indústrias de processamento de couro e curtumes, a serragem cromada, vem sendo estocada nas mesmas, constituíndo enormes pilhas de armazenamento nos pátios dessas indústrias. Mediante o exposto, a presente pesquisa... / The tanned leather waste is a type of solid waste generated in great amounts in tanneries and industries of leather processing in Brazil. From tehe environmental point of view it is considered to be a very problematic waste, since its classification is hazardous waste, according to the Brazilian rules, due to the presence of relatively high lixiviable concentrations of the element trivalent chromium used in the tanning process. The tanned leather waste destination tended to be the simple dropping on rubbish landfills without any type of control. More recently, due to pressures of the environmental control organs on the industries of leather processing and tanneries, the tanned leather waste has been stored inside the manufacturing facilities, becoming enormous strorage piles in those industries courtyards. By the exposed, this research proposes an appropriate way to the destination for... (Complete abstract click electronic access below)

Content: Tannins are high molecular weight polyphenols, naturally synthesized by plants to defend themselves against biotic and abiotic stress factors. Their role as antioxidant, antibiotic and antibacterial agent has been known for many years among agriculture, food, pharma and cosmetics industry. If tannins would perform an antibacterial activity in a vegetable tanned leather, the leather itself could be certified as an antibacterial material. This effect could be very interesting for all the applications in which the leather, being in contact with sweat and bacteria, becomes a solution to reduce more or less severe hyperhidrosis and bromhidrosis. The goal of the study was the assessment of the antibacterial activity of vegetable tanned leathers with natural tannins to produce articles in direct contact with human skin and, therefore, their effect on sweat, bacterial growth and metabolite production. Firstly, the antibacterial activity has been evaluated and compared between leathers tanned with Chestnut, Quebracho and Tara extracts, chrome tanned leathers and synthetic materials. The trial was performed in vitro by inoculating gram positive (Staphylococcus aureus) and gram negative (Escherichia coli) bacterial strains. A later step defined the most suitable blend of tannins to obtain, after tanning and/or retanning, an antibacterial natural leather. Furthermore, the vegetable tanned leathers, made with this tannins blend, have been the target of an in vivo trial during which 15 panelists have worn two differently made shoes. The lining and insole inside the right shoe have been made with vegetable tanned leathers with tannins, while the ones inside the left shoe contained only synthetic material. The shoes have been worn for 28 consecutive days, followed by a molecular and bioinformatic analysis of microbiota samples taken from the inner surface of the shoes by using a sterile swab. Lastly, a biochemical analysis of volatile short chain fatty acids has been carried out to investigate the byproducts of the bacteria responsible for the unpleasant odor of shoes. Take-Away: 1. Vegetable tanned leather is a wonderful antibacterial material thanks to the presence of natural tannins, such as chestnut, quebracho and tara. This property is appreciated in the production of insole leather, lining, leather goods and automotive interiors. 2. The problem of bromhidrosis (bad feet odor) can be avoided by using vegetable tanned leather. 3. In particular, vegetable leathers tanned with tannins used to make inside part of the shoes permit to avoid the formation of cheesy and acidic odours thanks to their antibacterial properties and their capacity to absorb sweat.

Content: The thermal degradation kinetics of hides before and after being tanned with formaldehyde were investigated using thermalgravimetric analysis (TGA) at four different heating rates of 5, 10, 20, 30 K/min. Such model-free methods as Flynn-Wall-Ozawa and Friedman as well as model-fitting method of Criado were employed to determine the thermal degradation active energy and degradation mechanism. Based on the Flynn-Wall-Ozawa and Friedman methods, the average active energy (Ea) of formaldehyde-tanned leather was 223.1 kJ/mol and 230.7 kJ/mol respectively. Results from general master curves showed diffusion processes in the thermal degradation of formaldehyde-tanned leather. Neither the thermal degradation activation energy nor the degradation mechanism is affected by the formaldehyde tanning. Nevertheless, the results by thermalgravimetric analyzer coupled with Fourier transform infrared spectrometry (TG-FTIR) indicated difference in the relative amounts of evolved products. According to the 3D-FTIR analysis, the dominant components of evolved gas for both untanned and tanned hides are CO2, CH4, H2O, NH3 along with small amount of HNCO. However, after formaldehyde tanning, both the evolved NH3 by the decomposition of free –NH2 groups and peptide –NH– groups from different amino acids in collagen and CH4 by the cleavage of -CH3 and -CH2- increase. Take-Away: 1. The theraml degradtion mechanism of hides before and after formaldehyde-tanning is eatablished in our paper. 2. The main degradation pathway of hides before and after formaldehyde-tanning is discussed with the help of TG-FTIR analysis.