Development of films based on blends of gelatin and poly(vinyl alcohol) cross linked with glutaraldehyde
Contribuinte(s) |
UNIVERSIDADE DE SÃO PAULO |
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Data(s) |
19/10/2012
19/10/2012
2011
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Resumo |
Both gelatin and poly(vinyl alcohol) (PVA) can be cross linked with glutaraldehyde (GLU). In the case of gelatin, the GLU reacts with each e-NH2 functional group of adjacent lysine residues, while for PVA, the GLU reacts with two adjacent hydroxyl groups, forming acetal bridges. Thus it can be considered possible to cross link adjacent macromolecules of gelatin and PVA using GLU. In this context, the aims of this work were the development of biodegradable films based on blends of gelatin and poly(vinyl alcohol) cross linked with GLU, and the characterization of some of their main physical and functional properties. All the films were produced from film-forming solutions (FFS) containing 2 g macromolecules (PVA + gelatin)/100 g FFS, 25 g glycerol/100 g macromolecules, and 4 g GLU (25% solution)/100 g FFS. The FFS were prepared with two concentrations of PVA (20 or 50 g PVA/100 g macromolecules) and two reaction temperatures: 90 or 55 degrees C, applied for 30 min. The films were obtained after drying (30 degrees C/24 h) and conditioning at 25 degrees C and 58% of relative humidity for 7 days, and were then characterized. The results for the color parameters, mechanical properties, phase transitions and infrared spectra showed that some chemical modifications occurred, principally for the gelatin. However, in general, all the characteristics of the films were either typical of films based on blends of these macromolecules without cross linking, or slightly higher. A greater improvement in the properties of this material was probably not observed due to the crystallinity of the PVA, which has a melting point above 90 degrees C. The presence of microcrystals in the polymer chain probably reduced macromolecular mobility, hindering the reaction. Thus more research is necessary to produce biodegradable films with improved properties. (C) 2011 Elsevier Ltd. All rights reserved. FAPESP[05/57781-8] FAPESP[08/53263-0] CNPq |
Identificador |
FOOD HYDROCOLLOIDS, v.25, n.7, p.1751-1757, 2011 0268-005X http://producao.usp.br/handle/BDPI/26827 10.1016/j.foodhyd.2011.03.018 |
Idioma(s) |
eng |
Publicador |
ELSEVIER SCI LTD |
Relação |
Food Hydrocolloids |
Direitos |
restrictedAccess Copyright ELSEVIER SCI LTD |
Palavras-Chave | #Biodegradable films #Biopolymer #Protein #Chemical modification #Physical properties #MECHANICAL-PROPERTIES #THERMAL-PROPERTIES #BIODEGRADABLE FILMS #PHYSICAL-PROPERTIES #COMPOSITE FILMS #WATER-CONTENT #EDIBLE FILMS #PVA #HYDROLYSIS #PROTEINS #Chemistry, Applied #Food Science & Technology |
Tipo |
article original article publishedVersion |