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Abstract(s)
A indústria têxtil e vestuário é importante para a economia da Europa e de Portugal, contudo,
causa grandes impactes ambientais, como elevado consumo de água nos seus processos e
consequente poluição, decorrente da utilização de produtos químicos para tingimento,
utilização de matérias-primas altamente poluentes como os corantes sintéticos e outros. A
presente pesquisa visa obter corantes naturais extraídos dos resíduos agroindustriais,
resultantes da produção de vinho (engaço, grainhas e pele das uvas) e produção da pinha dos
Pinheiro Manso e Pinheiro Bravo, criando uma alternativa sustentável para o tingimento de
têxteis. O processo de valorização destes resíduos em corantes têxteis pode passar pela
implementação de diversas estratégias eco-eficientes, como avaliação de ciclo de vida, eco design, produção mais limpa e economia circular. Contudo, numa primeira fase é necessário
analisar a potencialidade da sua utilização. Para a concretização dos objetivos, foram
realizadas analisada a composição química dos resíduos da videira e da mistura das pinhas do
Pinheiro Manso e Pinheiro Bravo. A pesquisa mostrou que as composições dos resíduos da
videira e da pinha são distintas, contudo são compostos de elevado valor. Os resíduos da
videira são mais representativos que a pinha, com a cinzas, hemicelulose e extratáveis em
diclorometano, etanol e água que representam 6,0%, 21,3%, 8,6%, 12,3% e 20,3%
respetivamente. Enquanto a pinha revelou possuir mais lenhina, alfacelulose 22,8%, 48,3%
que a videira. Também foram analisados os compostos químicos do resíduo da videira
acondicionados de maneira diferente (expostas ao ar e não expostas ao ar) por um período de
seis semanas, a fim de demostrar os efeitos da conservação na composição do resíduo. Foi
constatado que as amostras armazenadas não expostas ao ar sofreram maior degradação.
Contudo as duas amostras sofrem um aumento do teor de água, do pH e os extratáveis em
dicloromentano, mas os extratáveis em etanol e água reduziram. A deterioração também
causou a redução da alfacelulose e hemicelulose, resultando em um aumento das
concentrações da lenhina e das cinzas. Os ensaios de extração dos corantes da videira e da
pinha, em diferentes concentrações de NaOH (1%, 5%, 10% e 15%) extraem quantidades
crescentes de fenóis, entre 13,8% e 24,0%, no caso da videira, e entre 2,3% e 12,2% na pinha,
mas decrescentes de antioxidantes, entre 6,5% e 2,8%, na videira e 23,1 e 4,0% na pinha. Nos
testes de extração utilizando resíduos da videira armazenados por seis semanas, tanto expostos
ao ar quanto fechados, houve uma redução no pH e no teor de sólidos, enquanto os compostos
fenólicos e antioxidantes aumentaram. Todas essas características dos extratos influenciaram
na solidez da cor. Relativamente à coordenada L* (luminosidade), no tingimento com o
extrato da videira as cores ficaram mais escuras com acréscimo de NaOH, já com a pinha
ocorreu o contrário. Na coordenada a*, todas as amostras apresentaram tonalidade
avermelhada e na coordenada b*, todas as amostras apresentaram tonalidade amarelada. A
respeito da solidez à luz, todas as amostras foram afetadas pelo processo de foto-degradação,
porém os extratos da pinha demonstraram ser mais suscetível à luz do que os da videira. A
diferença cromática foi percetível à primeira vista, pois as amostras ficaram mais claras,
menos avermelhadas e mais amareladas. A respeito da solidez á luz, todas as amostras foram
afetadas pelo processo de foto-degradação, porém os extratos da pinha demonstraram ser mais
suscetível à luz do que a videira. A diferença cromática foi percetível à primeira vista, pois as
amostras ficaram mais claras, menos avermelhadas e mais amareladas. Em relação à solidez à
água, todas sofreram perda da cor, porém não foi percetível aos olhos humanos na maioria das
amostras.
ABSTRACT: The textile and clothing industry is important for the economy of Europe and Portugal, however, it causes major environmental impacts, such as high water consumption in its processes and consequent pollution, resulting from the use of chemical products for dyeing, the use of highly pollutants such as synthetic dyes and others. This research aims to obtain natural dyes extracted from agro-industrial waste, resulting from wine production (grape stems, seeds and skin) and production of stone pine and maritime pine cones, creating a sustainable alternative for dyeing textiles. The process of valuing these wastes into textile dyes can involve the implementation of several eco-efficient strategies, such as life cycle assessment, eco-design, cleaner production and circular economy. However, initially it is necessary to analyze the potential for its use. To achieve the objectives, the chemical composition of the vine residue and the mixture of stone pine and maritime pine cones were analyzed. Research has shown that the compositions of vine and pine cone residues are different, yet they are high-value compounds. Vine residues are more representative than pine cones, with ash, hemicellulose and extractables in dichloromethane, ethanol and water representing 6.0%, 21.3%, 8.6%, 12.3% and 20.3% respectively. While the pine cone revealed to have more lignin, alphacellulose 22.8%, 48.3% than the vine. The chemical compounds of vine residue conditioned differently (exposed to air and not exposed to air) for a period of six weeks were also analyzed, to demonstrate the effects of conservation on the composition of the residue. It was found that samples stored not exposed to air suffered greater degradation. However, both samples suffer an increase in water content, pH and extractables in dichloromethane, but extractables in ethanol and water have reduced. Spoilage also caused a reduction in alphacellulose and hemicellulose, resulting in an increase in lignin and ash concentrations. The dye extraction tests from vine and custard apple, in different concentrations of NaOH (1%, 5%, 10% and 15%) extract increasing amounts of phenols, between 13.8% and 24.0%, in the case of vine, and between 2.3% and 12.2% in the pine cone, but decreasing antioxidants, between 6.5% and 2.8%, in the vine and 23.1 and 4.0% in the pine cone. In extraction tests using vine residue stored for six weeks, both exposed to air and closed, there was a reduction in pH and solids content, while phenolic compounds and antioxidants increased. All these characteristics of the extracts influenced the color fastness. Regarding the L* coordinate (brightness), when dyeing with the vine extract, the colors became darker with the addition of NaOH, while with the pine cone the opposite occurred. In coordinate a*, all samples showed a reddish hue and in coordinate b*, all samples showed a yellowish hue. Regarding fastness to light, all samples were affected by the photo-degradation process, however the extracts from the pine cone proved to be more susceptible to light than those from the vine. The chromatic difference was noticeable at first glance, as the samples were lighter, less reddish and more yellowish. Regarding fastness to light, all samples were affected by the photo-degradation process, but the pine cone extracts proved to be more susceptible to light than the vine. The chromatic difference was noticeable at first glance, as the samples were lighter, less reddish and more yellowish. Regarding water fastness, all of them suffered color loss, but it was not perceptible to human eyes in most samples.
ABSTRACT: The textile and clothing industry is important for the economy of Europe and Portugal, however, it causes major environmental impacts, such as high water consumption in its processes and consequent pollution, resulting from the use of chemical products for dyeing, the use of highly pollutants such as synthetic dyes and others. This research aims to obtain natural dyes extracted from agro-industrial waste, resulting from wine production (grape stems, seeds and skin) and production of stone pine and maritime pine cones, creating a sustainable alternative for dyeing textiles. The process of valuing these wastes into textile dyes can involve the implementation of several eco-efficient strategies, such as life cycle assessment, eco-design, cleaner production and circular economy. However, initially it is necessary to analyze the potential for its use. To achieve the objectives, the chemical composition of the vine residue and the mixture of stone pine and maritime pine cones were analyzed. Research has shown that the compositions of vine and pine cone residues are different, yet they are high-value compounds. Vine residues are more representative than pine cones, with ash, hemicellulose and extractables in dichloromethane, ethanol and water representing 6.0%, 21.3%, 8.6%, 12.3% and 20.3% respectively. While the pine cone revealed to have more lignin, alphacellulose 22.8%, 48.3% than the vine. The chemical compounds of vine residue conditioned differently (exposed to air and not exposed to air) for a period of six weeks were also analyzed, to demonstrate the effects of conservation on the composition of the residue. It was found that samples stored not exposed to air suffered greater degradation. However, both samples suffer an increase in water content, pH and extractables in dichloromethane, but extractables in ethanol and water have reduced. Spoilage also caused a reduction in alphacellulose and hemicellulose, resulting in an increase in lignin and ash concentrations. The dye extraction tests from vine and custard apple, in different concentrations of NaOH (1%, 5%, 10% and 15%) extract increasing amounts of phenols, between 13.8% and 24.0%, in the case of vine, and between 2.3% and 12.2% in the pine cone, but decreasing antioxidants, between 6.5% and 2.8%, in the vine and 23.1 and 4.0% in the pine cone. In extraction tests using vine residue stored for six weeks, both exposed to air and closed, there was a reduction in pH and solids content, while phenolic compounds and antioxidants increased. All these characteristics of the extracts influenced the color fastness. Regarding the L* coordinate (brightness), when dyeing with the vine extract, the colors became darker with the addition of NaOH, while with the pine cone the opposite occurred. In coordinate a*, all samples showed a reddish hue and in coordinate b*, all samples showed a yellowish hue. Regarding fastness to light, all samples were affected by the photo-degradation process, however the extracts from the pine cone proved to be more susceptible to light than those from the vine. The chromatic difference was noticeable at first glance, as the samples were lighter, less reddish and more yellowish. Regarding fastness to light, all samples were affected by the photo-degradation process, but the pine cone extracts proved to be more susceptible to light than the vine. The chromatic difference was noticeable at first glance, as the samples were lighter, less reddish and more yellowish. Regarding water fastness, all of them suffered color loss, but it was not perceptible to human eyes in most samples.
Description
Keywords
Corantes naturais Tingimento Sustentável Valorização de resíduos Economia circular