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Development and Evaluation of a Novel pH Indicator Biodegradable Film Based on Cassava Starch

VEIGA-SANTOS, P.; DITCHFIELD, C.; TADINI, C. C.
Fonte: WILEY-BLACKWELL Publicador: WILEY-BLACKWELL
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
36.41%
A pH indicator film based on cassava starch plasticized with sucrose and inverted sugar and incorporated with grape and spinach extracts as pH indicator sources (anthocyanin and chlorophyll) has been developed, and its packaging properties have been assessed. A second-order central composite design (2(2)) with three central points and four star points was used to evaluate the mechanical properties (tensile strength, tensile strength at break, and elongation at break percentage), moisture barrier, and microstructure of the films, and its potential as a pH indicator packaging. The films were prepared by the casting technique and conditioned under controlled conditions (75% relative humidity and 23 degrees C), at least 4 days before the analyses. The materials were exposed to different pH solutions (0, 2, 7, 10, and 14) and their color parameters (L*, a*, b*, and haze) were measured by transmittance. Grape and spinach extracts have affected the material characterization. Film properties (mechanical properties and moisture barrier) were strongly influenced by extract concentration presenting lower results than for the control. Films containing a higher concentration of grape extract presented a greater color change at different pH`s suggesting that anthocyanins are more effective as pH indicators than chlorophyll or the mixture of both extracts. (C) 2010 Wiley Periodicals...

Study of some physical properties of biodegradable films based on blends of gelatin and poly(vinyl alcohol) using a response-surface methodology

CARVALHO, R. A.; MARIA, T. M. C.; MORALES, I. C. F.; BERGO, P. V. A.; KAMIMURA, E. S.; HABITANTE, A. M. Q. B.; SOBRAL, P. J. A.
Fonte: ELSEVIER SCIENCE BV Publicador: ELSEVIER SCIENCE BV
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
36.33%
The aim of this work was to study the effect of the hydrolysis degree (HD) and the concentration (C(PVA)) Of two types of poly(vinyl alcohol) (PVA) and of the type (glycerol and sorbitol) and the concentration (C(P)) of plasticizers on some physical properties of biodegradable films based on blends of gelatin and PVA Using a response-surface methodology. The films were prepared with a film forming solutions (FFS) with 2 g of macromolecules (gelatin+PVA)/100 g de FFS. The responses analyzed were the mechanical properties, the solubility, the moisture Content. the color difference and the opacity. The linear model was statistically significant and predictive for puncture force and deformation. elongation at break, solubility in water, Moisture content and opacity. The CPVA affected strongly the elongation at break of the films. The interaction of the HD and the C(P) affected this property. Moreover. the puncture force was affected slightly by the C(PVA). Concerning the Solubility in water, the reduction of the HD increased it and this effect was greater for high CPVA Values. In general. the most important effect observed in the physical properties of the films was that of the plasticizer type and concentration. The PVA hydrolysis degree and concentration have an important effect only for the elongation at break...

FT-Raman investigation of biodegradable polymers: Poly(3-hydroxybutyrate) and poly(3-hydroxybutyrate-co-3-hydroxyvalerate)

IZUMI, Celly M. S.; TEMPERINI, Marcia L. A.
Fonte: ELSEVIER SCIENCE BV Publicador: ELSEVIER SCIENCE BV
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
36.17%
This work presents a FT-Raman study (lambda(0) = 1064 nm) of naturally occurring polyester poly[(R)-3-hydroxybutyrate] (PHB) and its copolymer poly[(R)-3-hydroxybutyrate-co-(R)-3-hydroxyvalerate] (PHBV) with 5,8 and 12 mol % of HV (hydroxyvalerate). The FT-Raman spectra of films indicate that full width at half height of the band centered at 1725 cm(-1) and relative intensity of bands at 1443 and 1458 cm(-1) can be use to estimate the crystalline degree in film samples. The similarity between Raman spectra of molten PHB and PHBV and theirs CDCl(3) solutions suggested that molten polymers present similar conformation than polymers in solution. Raman data of these samples showed that bands at 1220, 1402, 1725, 2998 and 3009 cm(-1) are due to crystalline helical structure and the bands at 1453, 1740, 2881, 2938 and 2990 cm(-1) are originated from disordered domains. It is shown that composition of PHBV samples can be estimated by analyzing the ratio of the intensity of the bands at 2938 cm(-1) (nu C-H) and 1740 cm(-1) (nu C=O) in the spectra of solutions and of bands at 1354 (wCH(2)) and 1740 cm(-1) (nu C=O) in spectra of molten polymers. (C) 2010 Elsevier B.V. All rights reserved.

Development and optimization of biodegradable films based on achira flour

Andrade-Mahecha, Margarita Maria; Blácido, Delia Rita Tapia; Menegalli, Florencia Cecilia
Fonte: ELSEVIER SCI LTD; OXFORD Publicador: ELSEVIER SCI LTD; OXFORD
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
36.28%
The influence of glycerol concentration (C-g), process temperature (T-p), drying temperature (T-s), and relative humidity (RH) on the properties of achira flour films was initially assessed. The optimized process conditions were C-g of 17g glycerol/100g flour, T-p of 90 degrees C, T-s of 44.8 degrees C, and RH of 36.4%. The films produced under these conditions displayed high mechanical strength (7.0 MPa), low solubility (38.3%). and satisfactory elongation values (14.6%). This study showed that achira flour is a promising source for the development of biodegradable films with good mechanical properties, low water vapor permeability, and solubility compared to films based on other tubers. (c) 2011 Elsevier Ltd. All rights reserved.; CNPq (Conselho Nacional de Desenvolvimento Cientifico e Tecnologico); Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq); Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES); CAPES (Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior)

Adição de ingredientes antimicrobianos em filmes biodegradáveis à base de fécula de mandioca.; Addition of antimicrobial ingredients to biodegradable films based on cassava starch.

Kechichian, Viviane
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 16/04/2007 PT
Relevância na Pesquisa
36.28%
Neste trabalho, ingredientes naturais antimicrobianos foram adicionados em filme biodegradável (biofilme) à base de fécula de mandioca tendo como plastificantes sacarose e açúcar invertido. A seleção dos ingredientes antimicrobianos (cravo em pó, canela em pó, pimenta vermelha em pó, óleo essencial de laranja, café em pó, mel e extrato de própolis) foi conduzida por meio de um delineamento experimental (fatorial fracionado 27-3) e os biofilmes foram analisados quanto às suas propriedades de barreira (permeabilidade ao vapor de água e taxa de permeabilidade ao vapor de água) e propriedades mecânicas (resistência máxima à tração e porcentagem de alongamento na ruptura). Os biofilmes apresentaram valores inferiores aos apresentados pelo biofilme controle quanto às propriedades mecânicas. Em geral, a taxa de permeabilidade ao vapor de água nos biofilmes antimicrobianos manteve-se estatisticamente igual ao do controle. Na segunda etapa do trabalho, a otimização dos ingredientes selecionados foi realizada através de delineamento experimental, com somente adição de cravo e canela em pó, que apresentaram resultados mais promissores na etapa anterior. Foi constatado que a adição de cravo e canela em pó alterou as propriedades mecânicas...

Elaboração de filmes biodegradáveis a partir do resíduo da extração do pigmento de Cúrcuma; Development of biodegradable films from the residue of the extraction of the pigment from turmeric.

Maniglia, Bianca Chieregato
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 04/10/2012 PT
Relevância na Pesquisa
46.52%
Este trabalho teve como objetivo estudar o potencial do uso de farelo obtido do resíduo da extração do pigmento de cúrcuma (Cúrcuma longa L.) na elaboração de filmes biodegradáveis. Primeiramente, foi conduzido um estudo da extração de corante de cúrcuma por método Soxhlet para simular o processo industrial, dessa forma, utilizaram-se dois tipos de solventes, etanol: isopropanol (1:1) e metanol: acetona (1:1). A partir das tortas foi feito um processo de moagem e peneiragem na tentativa de isolar o amido presente, apesar de não ter obtido sucesso, este processo permitiu obter diferentes frações de farelo de cúrcuma. As frações foram divididas em 80 (F1), 200 (F2), 270 (F3), 400 (F4) mesh e fração centrifugada (F5). A caracterização das tortas de cúrcuma e das frações consistiu em análise da composição centesimal, MEV, difração de raios X e FTIR. A partir destas frações foram elaborados filmes pela metodologia casting. Os filmes foram caracterizados por MEV, difração de raios X, FTIR, análise antioxidante, propriedades mecânicas, solubilidade em água, umidade e permeabilidade ao vapor de água. Os filmes feitos a partir das frações (metanol:acetona) apresentaram melhores propriedades mecânicas e de barreira do que os feitos a partir da frações (etanol:isopropanol)...

Filme biodegradável à base de fécula de mandioca como potencial indicador de mudança de pH.; Biodegradable film based on cassava starch as patential indicator of pH change.

Zetty Arenas, Ana Maria
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 26/06/2012 PT
Relevância na Pesquisa
36.6%
A cada dia é mais crescente a necessidade e interesse no desenvolvimento de embalagens competitivas e com maior valor agregado. Visando atender a necessidade de consumidores cada vez mais exigentes e preocupados com o meio ambiente, este trabalho propôs o uso do pigmento natural antocianina no desenvolvimento de filmes biodegradáveis para potencial uso como embalagem inteligente, indicadora de mudança de pH. Os filmes foram elaborados pela técnica de casting tendo como formulação base fécula de mandioca (Manihot esculenta Crantz), argila esmectita sódica, glicerol, etanol e água, e incorporados com duas concentrações de antocianina (0,05 e 0,10) g/100 g de solução filmogênica, e em uma segunda fase, ácido cítrico foi incorporado à matriz polimérica a fim de estudar a influência do pH da solução filmogênica (2,8 e 4,3) sobre o desempenho do filme empregado como embalagem. Os filmes foram avaliados quanto as suas propriedades mecânicas (resistência máxima à tração e porcentagem de elongação na ruptura), físico-químicas (atividade de água, umidade, espessura), de barreira (permeabilidade ao vapor dágua e ao oxigênio) e análise de mudança de cor. Em seguida à caracterização, a atividade indicadora de pH foi testada com peixe cru embalado em recipientes de vidro tampados com o filme. Os recipientes foram acondicionados em temperatura ambiente e sob três temperaturas distintas de refrigeração...

Filmes biodegradáveis à base de proteína da torta de mamona: efeito do pH de extração das proteínas e do reforço com fibras de sisal e/ou glioxal; Biodegradable films made with proteins from castor bean cake: effect of protein extraction pH and sisal fiber and/or glyoxal reinforcement

Bittante, Ana Mônica Quinta Barbosa
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 29/06/2015 PT
Relevância na Pesquisa
36.68%
O Brasil e o terceiro maior produtor de mamona do mundo e o maior produtor da América do Sul. O óleo da mamona tem grande potencial na cadeia de produção de biodiesel, sendo interessante a geração de recursos dos subprodutos, como a torta de mamona. Apesar de ser rica em proteínas, a torta de mamona tem limitada aplicação em virtude da presença da ricina, que apresenta elevada toxidez. Assim, esperando-se valorizar esse subproduto com novas aplicações tecnológicas, o objetivo desta tese foi o desenvolvimento de filme biodegradável a partir da proteína extraída da torta de mamona. Especificamente, estudou-se o efeito do pH (10, 11 e 12) de extração das proteínas sobre algumas propriedades físicas (espessura, propriedades mecânicas, solubilidade em agua, permeabilidade ao vapor de agua e umidade) dos filmes produzidos. A partir da avaliação destes resultados, foi então definido o pH de extração da proteína da torta de mamona para o segundo estudo que envolveu a produção de filmes a base da proteína extraída da torta de mamona, reforçados com fibra de sisal e/ou glioxal. Primeiramente, as proteínas foram extraídas em um reator, adicionando-se 20% de torta de mamona na solução de NaOH (pH= 10, 11 e 12)...

Development and optimization of biodegradable films based on achira flour

Andrade-Mahecha, Margarita Maria; Tapia-Blacido, Delia Rita; Menegalli, Florencia Cecilia
Fonte: Elsevier; Oxford Publicador: Elsevier; Oxford
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
36.28%
The influence of glycerol concentration (C-g), process temperature (T-p), drying temperature (T-s), and relative humidity (RH) on the properties of achira flour films was initially assessed. The optimized process conditions were C-g of 17g glycerol/100g flour, T-p of 90 degrees C, T-s of 44.8 degrees C, and RH of 36.4%. The films produced under these conditions displayed high mechanical strength (7.0 MPa), low solubility (38.3%). and satisfactory elongation values (14.6%). This study showed that achira flour is a promising source for the development of biodegradable films with good mechanical properties, low water vapor permeability, and solubility compared to films based on other tubers. (c) 2011 Elsevier Ltd. All rights reserved.; Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES); Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Casein and soybean protein-based thermoplastics and composites as alternative biodegradable polymers for biomedical applications

Vaz, C. M.; Fossen, M.; Tuil, R. F. van; Graaf, L. A. de; Cunha, A. M.; Reis, R. L.
Fonte: Wiley Interscience Publicador: Wiley Interscience
Tipo: Artigo de Revista Científica
Publicado em /04/2003 ENG
Relevância na Pesquisa
36.17%
This work reports on the development and characterization of novel meltable polymers and composites based on casein and soybean proteins. The effects of inert (Al(2)O(3)) and bioactive (tricalcium phosphate) ceramic reinforcements over the mechanical performance, water absorption, and ioactivity behavior of the injection-molded thermoplastics were examined. It was possible to obtain materials and composites with a range of mechanical properties, which might allow for their application in the biomedical field. The incorporation of tricalcium phosphate into the soybean thermoplastic decreased its mechanical properties but lead to the nucleation of a bioactive calcium-phosphate film on their surface when immersed in a simulated body fluid solution. When compounded with 1% of a zirconate coupling agent, the nucleation and growth of the bioactive films on the surface of the referred to composites was accelerated. The materials degradation was studied for ageing periods up to 60 days in an isotonic saline solution. Both water uptake and weight loss were monitored as a function of the immersion time. After 1 month of immersion, the materials showed signal of chemical degradation, presenting weight losses up to 30%. However, further improvement on the mechanical performance and the enhancement of the hydrolytic stability of those materials will be highly necessary for applications in the biomedical field; Portuguese Foundation for Science and Tecnology (FCT)...

Avaliação do desempenho de diferentes plásticos biodegradáveis na cultura do morangueiro (Fragaria x ananassa Duch.)

Andrade, Maria Cláudia Pereira de Araújo Santos
Fonte: ISA/UTL Publicador: ISA/UTL
Tipo: Dissertação de Mestrado
Publicado em //2011 POR
Relevância na Pesquisa
46.72%
Mestrado em Engenharia do Ambiente - Instituto Superior de Agronomia; An enormous amount of plastic waste resulting from the agricultural activities is produced every year. Part of this plastic remains in the fields, while the other part is sent to recycling or landfill. The use of biodegradable mulch films can play an important role towards a sustainable development in agricultural sector. These plastics can be plugged in the soil, after its use, among the crop residues. The aim of this study was to compare the performance of three different biodegradable mulch films (P1, P2 and P3) against the conventional polyethylene mulch film (P4), in the production of strawberries, during the autumn-winter cycle. The parameters followed during the crop cycle were yield, plant growth, fruit quality and pests and diseases. The biodegradable mulch films had different behaviors during the crop cycle, P3 showing the best performance with 85% soil coverage at the end of the crop cycle, followed by P2 and P1 with 70% and 20%, respectively. The soil coverage of the conventional mulch film was 100%. Compared to conventional mulch film, biodegradable mulches led to a decrease in the yield and in the harvest index, while there was an increase in the total dry biomass of the plants. Results obtained also showed that overall quality of fruits was not affected by the type of plastic. As a conclusion...

Estudo da biodegradabilidade de bioplásticos numa cultura de ciclo longo - morango

Costa, Raquel Alexandra Cardoso
Fonte: ISA/UTL Publicador: ISA/UTL
Tipo: Dissertação de Mestrado
Publicado em //2012 POR
Relevância na Pesquisa
36.39%
Mestrado em Engenharia do Ambiente - Instituto Superior de Agronomia; The use of plastic mulch in agriculture had its beginning in the middle of last century and since then its use has been intensified and the costs of send this residue to appropriate final destination lead it often to be left or burned in open field, causing huge environmental concerns. The biodegradable mulch films, which can be incorporated in the soil at the end of the crop appear as a possible solution for this problem. The goal of this work was to test the biodegradability of 5 plastic mulches, made from biodegradable polymers, comparing to conventional Polyethylene (PE). The biodegradability was tested in laboratory by means of a respirometric test that followed the standard EN ISO 17 556, and in field conditions, by observation and calculation of the percentage of area lost, along the time, in net frames containing the various biodegradable plastics. The field trials to assess fruit productivity and quality were performed during two years. One of the biodegradable mulches stands out for its good performance and seems as a very promising mulch that may be a viable replacement for conventional polyethylene.

Starch/polyester films: simultaneous optimisation of the properties for the production of biodegradable plastic bags

Olivato,J. B.; Grossmann,M. V. E.; Bilck,A. P.; Yamashita,F.; Oliveira,L. M.
Fonte: Associação Brasileira de Polímeros Publicador: Associação Brasileira de Polímeros
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2013 EN
Relevância na Pesquisa
36.43%
Blends of starch/polyester have been of great interest in the development of biodegradable packaging. A method based on multiple responses optimisation (Desirability) was used to evaluate the properties of tensile strength, perforation force, elongation and seal strength of cassava starch/poly(butylene adipate-co-terephthalate) (PBAT) blown films produced via a one-step reactive extrusion using tartaric acid (TA) as a compatibiliser. Maximum results for all the properties were set as more desirable, with an optimal formulation being obtained which contained (55:45) starch/PBAT (88.2 wt. (%)), glycerol (11.0 wt. (%)) and TA (0.8 wt. (%)). Biodegradable plastic bags were produced using the film with this formulation, and analysed according to the standard method of the Associação Brasileira de Normas Técnicas (ABNT). The bags exhibited a 45% failure rate in free-falling dart impact tests, a 10% of failure rate in dynamic load tests and no failure in static load tests. These results meet the specifications set by the standard. Thus, the biodegradable plastic bags fabricated with an optimised formulation could be useful as an alternative to those made from non-biodegradable materials if the nominal capacity declared for this material is considered.

Development and characterization of hybrid materials based on biodegradable PLA matrix, microcrystalline cellulose and organophilic silica

Santos,Fernanda Abbate dos; Tavares,Maria Inês Bruno
Fonte: Associação Brasileira de Polímeros Publicador: Associação Brasileira de Polímeros
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/10/2014 EN
Relevância na Pesquisa
36.33%
The goal of this work was to investigate the production and properties of hybrid materials based on poly(lactic acid) (PLA), employing microcrystalline cellulose (MCC) and organophilic silica (R972) as fillers. The composites were obtained by solution casting to form films. Each nanoparticle was incorporated at 3 wt. %, relative to the polymer matrix. In this experiment, four films were obtained (PLA, PLA/MCC, PLA/R972 and PLA/MCC/R972). The films properties were evaluated by X-ray diffractometry, nuclear magnetic resonance, Fourier transform infrared spectroscopy and mechanical properties. The results showed that each nanoparticle, added individually or both combined, had different effect on the final properties of the films. Microcrystalline cellulose can act as nucleating agent for the crystallization of PLA. Silica promoted an increase in rigidity, due to the strong intermolecular forces, while MCC addition promoted an increase in the molecular mobility of the polymeric chains. The PLA/MCC/R972 film showed the highest crystallinity degree and tensile modulus. This film presented a T1H value between both values found for PLA/MCC and PLA/R972 films. The results indicated that silica R972 could promote a decrease of the surface tension between PLA and cellulose.

Influência do pH e da irradiação em filmes biodegradáveis de proteínas do soro de leite; Influence of ph and irradiation in whey proteins biodegradable films

SOARES, Dayana Silva Batista
Fonte: Universidade Federal de Goiás; BR; UFG; Mestrado em Ciência e Tecnologia de Alimentos; Ciencias Agrárias - Agronomia Publicador: Universidade Federal de Goiás; BR; UFG; Mestrado em Ciência e Tecnologia de Alimentos; Ciencias Agrárias - Agronomia
Tipo: Dissertação Formato: application/pdf
POR
Relevância na Pesquisa
36.39%
The packaging has as main function to maintain the integrity of the product, protecting it against mechanical damage, moisture loss and gain. Most packaging is manufactured from non-biodegradable materials and non-renewable source promoting great environmental impacts. Among the raw materials used in the development of biodegradable films found the whey proteins. The biodegradables films do not present the same resistance presented for the synthetic films, many treatments are being applied to biofilmes in the attempt to improve the mechanical properties, amongst them the variation of pH and irradiation. In this way, aimed to evaluate the effect of different pH values and doses of gamma radiation on the mechanical, optical and barrier properties of whey proteins biodegradable films. The films were made by casting and characterized with respect to thickness, color, opacity, water vapor permeability, water solubility, scanning electron microscopy and mechanical properties. The different treatments studied significantly influenced the properties of the films, except for the water solubility. It is concluded that the different treatments can promote improvement in film properties.; A embalagem tem como função principal manter a integridade do produto...

Avaliação e caracterização das propriedades filmogênicas de proteínas do soro de leite submetidas à irradiação e modificação de pH; Evaluation and characterization of whey film protein properties submitted to radiation and modification of pH

Fernandes, Ana Paula Stort
Fonte: Universidade Federal de Goiás; Brasil; UFG; Programa de Pós-graduação em Ciência e Tecnologia de Alimentos (EAEA); Escola de Agronomia e Engenharia de Alimentos - EAEA (RG) Publicador: Universidade Federal de Goiás; Brasil; UFG; Programa de Pós-graduação em Ciência e Tecnologia de Alimentos (EAEA); Escola de Agronomia e Engenharia de Alimentos - EAEA (RG)
Tipo: Dissertação Formato: application/pdf
POR
Relevância na Pesquisa
36.39%
The packages comprise a large part of the daily disposal of household waste and these household waste are the most impactful to the environment. The development of biodegradable packaging material, seeking to replace synthetic polymers, is an approach used in an attempt to reduce the environmental impact caused by the very slow degradation of synthetic material packages. It is known that the development of biomaterials, applicable to various industries technology in the area of packaging, gaining particular attention on the issue of preserving the environment. The aim of this study was to develop a biodegradable films of whey protein irradiated subjected to pH modification, and evaluate their mechanical, optical, structural and barrier properties. The experiment was conducted in the Department of Food Engineering, College of Agronomy, Federal University of Goiás (UFG), located in Goiânia (GO). The protein concentrate, whey was supplied by the Argentine company Arla Foods. Statistical analysis was performed by analysis of variance (ANOVA) and Tukey test (p ≤ 0.05). The computer program Version 2.15.1 R (Vienna, Austria) was used for calculations. In the experiment, all analyzes were performed with three replicates read in triplicate except mechanical tests...

Film blowing of PHBV blends and PHBV-based multilayers for the production of biodegradable packages

Cunha, Mara; Fernandes, Bruno Daniel; Covas, J. A.; Vicente, A. A.; Hilliou, L.
Fonte: John Wiley & Sons Inc. Publicador: John Wiley & Sons Inc.
Tipo: Artigo de Revista Científica
Publicado em 10/01/2016 ENG
Relevância na Pesquisa
36.67%
Poly(hydroxy butyrate-co-valerate) (PHBV) is a biodegradable polymer that is difficult to melt process into films. Such difficulty is mirrored in the lack of literature on film blowing of PHBV- or PHBV-based materials. To circumvent this problem, 70/30 wt % blends of PHBV with a biodegradable compound (PBSebT), or with poly(butylene adipate-co-terephtalate) (PBAT), were prepared and tested for extrusion film blowing. Both blends showed a similar rheological pattern at 175°C, which is the maximum processing temperature with tolerable thermal degradation. Blending stabilized the film bubbles, thus widening the processing window. However, film properties such as tensile modulus, strain at break and tear resistance remained isotropic and crystallinity characteristics in the machine and transverse directions were generally similar. To bypass the thermal degradation associated with polymer blending, PHBV/PBAT films were coextruded. These showed enhanced functional properties when compared with films blown from blends. The mechanical properties of bilayered films matched those of films blown from commercial PBAT designed for food packaging.

Characterization of biodegradable film based on zein and oleic acid added with nanocarbonate

Ribeiro,Wanessa Ximenes; Lopes Filho,José Francisco; Cortes,Monica Souza
Fonte: Universidade Federal de Santa Maria Publicador: Universidade Federal de Santa Maria
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/10/2015 EN
Relevância na Pesquisa
36.33%
Zein oleic acid films added with 1, 2 and 3 % (w/w) of nanocarbonate and 30 % glycerol as plasticizer, were produced and evaluated according to their structure and functional properties. Structural characteristics were analyzed by optical and scanning electron microscopy (SEM). Water solubility and mechanical properties were determined according to ASTM methods. The increase of nanocarbonate concentration increased water solubility and influenced the color and mechanical properties. Optical and SEM of film samples added with nanocarbonate, shown low amount of pores and great fat globules size.

Comparative performance and barrier properties of biodegradable thermoplastics and nanobiocomposites vs. PET for food packaging applications

Cava, David; Giménez, Enrique; Gavara, Rafael; Lagarón Cabello, José María
Fonte: Society of Plastics Engineers Publicador: Society of Plastics Engineers
Tipo: Artículo Formato: 235434 bytes; 2459 bytes; application/pdf; text/plain
ENG
Relevância na Pesquisa
36.28%
This article reports on preliminary studies of several comparative packaging properties between polyethylene terephthalate (PET) packaging films and biodegradable biopolymers such as polycarpolactone (PCL), polylacticacid (PLA), amorphous PLA (aPLA), and polyhydroxyalcanoates copolymer with 8 mol% valeriate (PHBV) and of some nanobiocomposites, in terms of thermal and retorting resistance (thermal humid processes) and oxygen, water vapor, aroma, and solvent barrier by means of time-resolved synchrotron radiation, FT-IR and direct permeation methods. This work suggests that while PHBV can easily withstand retorting and shows excellent water and aroma (limonene and linalool) barriers compared with PET, its solvent resistance (toluene and ethanol) and oxygen barrier properties are poorer. First trials with compression molded food contact complying nanobiocomposites of PCL and aPLA show enhanced oxygen barrier but not sufficient, as yet, to outperform high-oxygen-barrier grades of PET film.

Formulation and stability of biodegradable films made from cod gelatin and sunflower oil blends

Pérez Mateos, Miriam; Montero García, Pilar; Gómez Guillén, M. C.
Fonte: Elsevier Publicador: Elsevier
Tipo: Artículo Formato: 259768 bytes; application/pdf
ENG
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9 pages, 2 tables, 3 figures.-- Printed version published Jan 2009.; Sunflower oil was added to cod gelatin in proportions of 0%, 0.3%, 0.6%, and 1% to improve the hydrophobic properties of the resulting films and decrease water vapor permeability and the soluble matter content. Mechanical and optical properties were evaluated to determine the influence of the added oil and the stability of the films during storage for one month. Adding oil increased film thickness, whiteness, optical absorbance and decreased transparency; all these properties held stable over the storage period. Fourier transform infrared (FTIR) spectra revealed some lipid–protein interactions (hydrogen bonds, ester formation) and early oil oxidation. By the end of storage oxidation was well advanced and secondary oxidation products were present. Adding oil in any quantity decreased the puncture force but not the puncture deformation. Stability of these two mechanical properties decreased during storage in the films that contained 0.6% added oil. Water vapor permeability did not decrease when oil was added and even increased with storage time, though adding oil yielded more insoluble films due to lipid–protein interactions.; This research was supported by the Spanish Ministry of Education and Science under Project AGL2005-02380/ALI and Project CYTED XI.20.; Peer reviewed