Desenvolvimento de filmes à base de goma de cajueiro modificada e goma kappa com reforço de nanocelulose

Detalhes bibliográficos
Autor(a) principal: Lima, Ana Cristina Silva de
Data de Publicação: 2019
Tipo de documento: Tese
Idioma: por
Título da fonte: Repositório Institucional da Universidade Federal do Ceará (UFC)
Texto Completo: http://www.repositorio.ufc.br/handle/riufc/41456
Resumo: Cashew gum (CG) has been exploited as a matrix for food films, but due to its hydrophilic characteristics, it presents low barrier properties that limit its application. Alternatives such as chemical modification, use of nanotechnology and addition of other polysaccharides to the blends formulation, allow to check improvements in physical, barrier and mechanical characteristics in filmogenic matrices. In this sense, the objective of this work was to modify GC with sodium trimetaphosphate (STMP) and to develop films based on modified cashew gum and kappa gum (KG) added with cellulose nanocomposite (CN). In general, the incorporation of NC and STMP showed a positive contribution to the water vapor barrier of the films, presenting values ranging from 3.71 to 5.3 g/h.m.Pa. This increase is due to the low hygroscopicity of the cellulose nanocrystals and the crosslinking of the gum. The films obtained in this study varied their solubility from 69.22% to 94.37%, where there was a significant difference (p <0.05) between treatments. These results indicate a good interaction of the CG and STMP chains, facilitated by a good dispersion of the CN in the polymer matrix. For the mechanical properties, the addition of nanoparticle had a positive effect, indicating that higher CN percentages provide films with higher tensile strength, elongation and rupture stress. In relation to the thermal analysis, four stages of mass loss were observed for CG/KG films. The second transition region (composed of two peaks or stages) was observed above the temperature of 200 °C to ± 450 °C. In this region, shoulders were observed on the DTG curve at about 230 °C before the major decomposition peak. The division of the second stage into two (forming shoulders) would be related to the fact that films are composed of more than one polymer matrix, which leads to different degradation behavior. For the FT-IR, the spectra of the nanocomposite films presented some of the main bands from the CG and KG, with changes in the intensity and some displacements, presenting few differences when compared to the pure CG sample, with characteristic peaks in the bands 2927 cm-1, 1637 cm-1 and 1074 cm-1. In the SEM, the films show a rough surface with imperfections, but no cracks, except the sample T4 and T8, which presented cracks in its surface, fact attributed to the concentration of the TMS crosslinking agent. It was observed that the contact angles presented values between 49.08° and 78.88°, suggesting that there was a decrease in the interaction between the water and the hydrophilic sites. In relation to the color parameter, the films had a brightness value between 89 and 91, considered clear, indicating a good transparency. In relation to the parameters a* and b*, they presented positive values for both parameters, indicating that they showed tendency to reddish and yellow, resulting in orange coloration.
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spelling Desenvolvimento de filmes à base de goma de cajueiro modificada e goma kappa com reforço de nanoceluloseDevelopment of films based on modified cashew gum and kappa gum with nanocellulose reinforcementBiopolímerosDesign experimentalPermeabilidade ao vapor de águaMolhabilidadeCor instrumentalCashew gum (CG) has been exploited as a matrix for food films, but due to its hydrophilic characteristics, it presents low barrier properties that limit its application. Alternatives such as chemical modification, use of nanotechnology and addition of other polysaccharides to the blends formulation, allow to check improvements in physical, barrier and mechanical characteristics in filmogenic matrices. In this sense, the objective of this work was to modify GC with sodium trimetaphosphate (STMP) and to develop films based on modified cashew gum and kappa gum (KG) added with cellulose nanocomposite (CN). In general, the incorporation of NC and STMP showed a positive contribution to the water vapor barrier of the films, presenting values ranging from 3.71 to 5.3 g/h.m.Pa. This increase is due to the low hygroscopicity of the cellulose nanocrystals and the crosslinking of the gum. The films obtained in this study varied their solubility from 69.22% to 94.37%, where there was a significant difference (p <0.05) between treatments. These results indicate a good interaction of the CG and STMP chains, facilitated by a good dispersion of the CN in the polymer matrix. For the mechanical properties, the addition of nanoparticle had a positive effect, indicating that higher CN percentages provide films with higher tensile strength, elongation and rupture stress. In relation to the thermal analysis, four stages of mass loss were observed for CG/KG films. The second transition region (composed of two peaks or stages) was observed above the temperature of 200 °C to ± 450 °C. In this region, shoulders were observed on the DTG curve at about 230 °C before the major decomposition peak. The division of the second stage into two (forming shoulders) would be related to the fact that films are composed of more than one polymer matrix, which leads to different degradation behavior. For the FT-IR, the spectra of the nanocomposite films presented some of the main bands from the CG and KG, with changes in the intensity and some displacements, presenting few differences when compared to the pure CG sample, with characteristic peaks in the bands 2927 cm-1, 1637 cm-1 and 1074 cm-1. In the SEM, the films show a rough surface with imperfections, but no cracks, except the sample T4 and T8, which presented cracks in its surface, fact attributed to the concentration of the TMS crosslinking agent. It was observed that the contact angles presented values between 49.08° and 78.88°, suggesting that there was a decrease in the interaction between the water and the hydrophilic sites. In relation to the color parameter, the films had a brightness value between 89 and 91, considered clear, indicating a good transparency. In relation to the parameters a* and b*, they presented positive values for both parameters, indicating that they showed tendency to reddish and yellow, resulting in orange coloration.A goma de cajueiro (GC) tem sido explorada como matriz para filmes alimentícios, porém devido a suas características hidrofílicas, apresentam baixas propriedades de barreira que limitam sua aplicação. Alternativas como a modificação química, uso da nanotecnologia e adição de outros polissacaríedos para a formulação de blendas, permitem conferir melhorias nas características físicas, de barreira e mecânicas em matrizes filmogênicas. Nesse sentido, este trabalho teve como objetivo modificar a GC com trimetafosfato de sódio (TMS) e desenvolver filmes à base de goma de cajueiro modificada e goma kappa (GK) adicionadas de nanocompósito de celulose (NC). De forma geral, a incorporação de NC e TMS mostaram um contribuição positiva em relação à barreira ao vapor de água dos filmes, apresentando valores que variaram de 3,71 a 5,3 g/h.m.Pa. Esse aumento se deve à baixa higroscopicidade dos nanocristais de celulose e da reticulação da goma. Os filmes obtidos neste estudo variaram sua solubilidade de 69,22% a 94,37%, onde houve diferença significativa (p<0,05) entre os tratamentos. Estes resultados indicam uma boa interação das cadeias de GC e TMS, facilitados por uma boa dispersão da NC na matriz polimérica. Para as propriedades mecânicas, a adição de nanopartícula teve um efeito positivo, indicando que maiores porcentagens de NC proporcionam filmes com maior resistência à tração, elongação e tensão na ruptura. Em relação às análises térmicas, quatro estágios de perda de massa foram observados para os filmes de CG/GK. A segunda região de transição (composta por dois picos ou estágios) foi observada acima da temperatura de 200 °C a ±450°C. Nessa região, foram observados ombros na curva DTG a cerca de 230 °C antes do pico principal de decomposição. A divisão do segundo estágio em dois (formando ombros), estaria relacionada ao fato dos filmes serem compostos por mais de uma matriz polimérica, o que leva a comportamentos de degradação distintos. Para o FT-IR, os espectros dos filmes nanocompósitos apresentaram algumas das principais bandas oriundas da GC e da GK, com modificações na intensidade e alguns deslocamentos, apresentando poucas diferenças se comparados à amostra de GC pura, com picos característicos nas bandas 2927 cm-1, 1637 cm-1 e 1074 cm-1. Na MEV, os filmes mostram uma superfície rugosa com imperfeições, mas sem rachaduras, exceto a amostra T4 e T8, as quais apresentaram rachaduras em sua superfície, fato atribuído à concentração do agente reticulante TMS. Foi observado que os ângulos de contato apresentaram valores, entre 49,08° e 78,88°, sugerindo que houve diminuição da disponibilidade de interação entre a água e os sítios hidrofílicos. Em relação ao parametro de cor, os filmes apresentaram valor de luminosidade entre 89 e 91, considerados claros, indicando assim uma boa transparência. Em relação aos parâmetros a* e b*, apresentaram valores positivos para ambos parâmetros, indicando que apresentaram tendência ao avermelhamento e amarelamento, resultando em coloração alaranjada.Figueiredo, Raimundo Wilane deLima, Ana Cristina Silva de2019-05-07T15:20:48Z2019-05-07T15:20:48Z2019info:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/doctoralThesisapplication/pdfLIMA, Ana Cristina Silva. Desenvolvimento de filmes à base de goma de cajueiro modificada e goma kappa com reforço de nanocelulose. 2019. 121 f. Tese (Doutorado em Biotecnologia) - Universidade Federal do Ceará, Fortaleza, 2019.http://www.repositorio.ufc.br/handle/riufc/41456porreponame:Repositório Institucional da Universidade Federal do Ceará (UFC)instname:Universidade Federal do Ceará (UFC)instacron:UFCinfo:eu-repo/semantics/openAccess2020-06-19T14:03:39Zoai:repositorio.ufc.br:riufc/41456Repositório InstitucionalPUBhttp://www.repositorio.ufc.br/ri-oai/requestbu@ufc.br || repositorio@ufc.bropendoar:2024-09-11T18:18:47.401147Repositório Institucional da Universidade Federal do Ceará (UFC) - Universidade Federal do Ceará (UFC)false
dc.title.none.fl_str_mv Desenvolvimento de filmes à base de goma de cajueiro modificada e goma kappa com reforço de nanocelulose
Development of films based on modified cashew gum and kappa gum with nanocellulose reinforcement
title Desenvolvimento de filmes à base de goma de cajueiro modificada e goma kappa com reforço de nanocelulose
spellingShingle Desenvolvimento de filmes à base de goma de cajueiro modificada e goma kappa com reforço de nanocelulose
Lima, Ana Cristina Silva de
Biopolímeros
Design experimental
Permeabilidade ao vapor de água
Molhabilidade
Cor instrumental
title_short Desenvolvimento de filmes à base de goma de cajueiro modificada e goma kappa com reforço de nanocelulose
title_full Desenvolvimento de filmes à base de goma de cajueiro modificada e goma kappa com reforço de nanocelulose
title_fullStr Desenvolvimento de filmes à base de goma de cajueiro modificada e goma kappa com reforço de nanocelulose
title_full_unstemmed Desenvolvimento de filmes à base de goma de cajueiro modificada e goma kappa com reforço de nanocelulose
title_sort Desenvolvimento de filmes à base de goma de cajueiro modificada e goma kappa com reforço de nanocelulose
author Lima, Ana Cristina Silva de
author_facet Lima, Ana Cristina Silva de
author_role author
dc.contributor.none.fl_str_mv Figueiredo, Raimundo Wilane de
dc.contributor.author.fl_str_mv Lima, Ana Cristina Silva de
dc.subject.por.fl_str_mv Biopolímeros
Design experimental
Permeabilidade ao vapor de água
Molhabilidade
Cor instrumental
topic Biopolímeros
Design experimental
Permeabilidade ao vapor de água
Molhabilidade
Cor instrumental
description Cashew gum (CG) has been exploited as a matrix for food films, but due to its hydrophilic characteristics, it presents low barrier properties that limit its application. Alternatives such as chemical modification, use of nanotechnology and addition of other polysaccharides to the blends formulation, allow to check improvements in physical, barrier and mechanical characteristics in filmogenic matrices. In this sense, the objective of this work was to modify GC with sodium trimetaphosphate (STMP) and to develop films based on modified cashew gum and kappa gum (KG) added with cellulose nanocomposite (CN). In general, the incorporation of NC and STMP showed a positive contribution to the water vapor barrier of the films, presenting values ranging from 3.71 to 5.3 g/h.m.Pa. This increase is due to the low hygroscopicity of the cellulose nanocrystals and the crosslinking of the gum. The films obtained in this study varied their solubility from 69.22% to 94.37%, where there was a significant difference (p <0.05) between treatments. These results indicate a good interaction of the CG and STMP chains, facilitated by a good dispersion of the CN in the polymer matrix. For the mechanical properties, the addition of nanoparticle had a positive effect, indicating that higher CN percentages provide films with higher tensile strength, elongation and rupture stress. In relation to the thermal analysis, four stages of mass loss were observed for CG/KG films. The second transition region (composed of two peaks or stages) was observed above the temperature of 200 °C to ± 450 °C. In this region, shoulders were observed on the DTG curve at about 230 °C before the major decomposition peak. The division of the second stage into two (forming shoulders) would be related to the fact that films are composed of more than one polymer matrix, which leads to different degradation behavior. For the FT-IR, the spectra of the nanocomposite films presented some of the main bands from the CG and KG, with changes in the intensity and some displacements, presenting few differences when compared to the pure CG sample, with characteristic peaks in the bands 2927 cm-1, 1637 cm-1 and 1074 cm-1. In the SEM, the films show a rough surface with imperfections, but no cracks, except the sample T4 and T8, which presented cracks in its surface, fact attributed to the concentration of the TMS crosslinking agent. It was observed that the contact angles presented values between 49.08° and 78.88°, suggesting that there was a decrease in the interaction between the water and the hydrophilic sites. In relation to the color parameter, the films had a brightness value between 89 and 91, considered clear, indicating a good transparency. In relation to the parameters a* and b*, they presented positive values for both parameters, indicating that they showed tendency to reddish and yellow, resulting in orange coloration.
publishDate 2019
dc.date.none.fl_str_mv 2019-05-07T15:20:48Z
2019-05-07T15:20:48Z
2019
dc.type.status.fl_str_mv info:eu-repo/semantics/publishedVersion
dc.type.driver.fl_str_mv info:eu-repo/semantics/doctoralThesis
format doctoralThesis
status_str publishedVersion
dc.identifier.uri.fl_str_mv LIMA, Ana Cristina Silva. Desenvolvimento de filmes à base de goma de cajueiro modificada e goma kappa com reforço de nanocelulose. 2019. 121 f. Tese (Doutorado em Biotecnologia) - Universidade Federal do Ceará, Fortaleza, 2019.
http://www.repositorio.ufc.br/handle/riufc/41456
identifier_str_mv LIMA, Ana Cristina Silva. Desenvolvimento de filmes à base de goma de cajueiro modificada e goma kappa com reforço de nanocelulose. 2019. 121 f. Tese (Doutorado em Biotecnologia) - Universidade Federal do Ceará, Fortaleza, 2019.
url http://www.repositorio.ufc.br/handle/riufc/41456
dc.language.iso.fl_str_mv por
language por
dc.rights.driver.fl_str_mv info:eu-repo/semantics/openAccess
eu_rights_str_mv openAccess
dc.format.none.fl_str_mv application/pdf
dc.source.none.fl_str_mv reponame:Repositório Institucional da Universidade Federal do Ceará (UFC)
instname:Universidade Federal do Ceará (UFC)
instacron:UFC
instname_str Universidade Federal do Ceará (UFC)
instacron_str UFC
institution UFC
reponame_str Repositório Institucional da Universidade Federal do Ceará (UFC)
collection Repositório Institucional da Universidade Federal do Ceará (UFC)
repository.name.fl_str_mv Repositório Institucional da Universidade Federal do Ceará (UFC) - Universidade Federal do Ceará (UFC)
repository.mail.fl_str_mv bu@ufc.br || repositorio@ufc.br
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