IFLP   13074
INSTITUTO DE FISICA LA PLATA
Unidad Ejecutora - UE
artículos
Título:
AN INSIGHT INTO THE ROLE OF GLYCEROL IN CHITOSAN FILMS
Autor/es:
S.RIVERO; L.C. DAMONTE; M.A.GARCÍA; A.PINOTTI
Revista:
FOOD BIOPHYSICS
Editorial:
SPRINGER
Referencias:
Lugar: Berlin; Año: 2015
ISSN:
1557-1858
Resumen:
This work was focused on assessing the influence of the glycerol in chitosan matrices,analyzing the changes produced in the molecular mobility, mechanical, thermal, barrier andstructural properties.The addition of glycerol in the matrix decreased the stress values, increasing the elasticity andwater vapor permeability of the films, with a marked decrease in glass transition temperature;Detailed analyses of Fourier Transform IR Spectroscopy spectra supported the observedchanges, especially in the spectral windows 1700-1500 cm-1revealing the modifications atmolecular level caused by hydrogen bond interactions between chitosan and water in thepresence of glycerol. Positron annihilation spectroscopic (PALS) measurements alloweddetermining the free volume assuming spherical holes as well as monitoring the structuralchanges in chitosan films caused by the addition of both, glycerol and water molecules. It waspossible to infer that for unplasticized matrices, a sustained increase of the radius between0.06 and 0.2 was observed, followed by a plateau up to 0.35. In the other case, with theaddition of glycerol, there were two plateaus, the first between 0.25 and 0.37, and the second from 0.41 to 0.47.For higher glycerol concentrations, the plasticizer would be mainly bounded to the chitosanpack more efficiently and the water present in the system would be predominantly free in the matrix causing its swelling. Findings on molecular mobility contributed to the understandingof the role of water and glycerol in the structural arrangement and its influence on film properties.