Reduction of enthalpy relaxation in gelatine films by addition of polyols

Paulo Díaz Calderón, Bill MacNaughtan, Sandra Hill, John Mitchell, Javier Enrione

Resultado de la investigación: Contribución a una revistaArtículorevisión exhaustiva

5 Citas (Scopus)

Resumen

The aim of this study was to evaluate the effect of plasticisers with different molecular weights (glycerol and sorbitol) on the structural relaxation kinetics of bovine gelatine films stored under the glass transition temperature (Tg). Plasticisers were tested at weight fractions of 0.0, 0.06 and 0.10. Films conditioned in environments under ∼44% relative humidity gave moisture contents (w/w) in the range 0.14–0.18. The enthalpy relaxation (ΔH) was determined using differential scanning calorimetry (DSC). Samples used had Tg values in the range 24–49 °C. After removing the thermal history (30 °C above Tg, 15 min), samples were isothermally stored at 10 °C below Tg for between 2 and 80 h. The addition of plasticisers induced a significant reduction in the rate of structural relaxation. The linearisation of ΔH by plotting against the logarithm of ageing time showed a reduction in the slope of samples plasticised with both polyols. The reduction in relaxation kinetics may be related to the ability of polyols to act as enhancers of molecular packing, as recently reported using positron spectroscopy (PALS). However, a direct correlation between the relaxation kinetics and the plasticiser's molecular weight could not be established, suggesting that this phenomenon may be governed by complex molecular gelatin-plasticiser-water interactions.

Idioma originalInglés
Páginas (desde-hasta)634-638
Número de páginas5
PublicaciónInternational Journal of Biological Macromolecules
Volumen109
DOI
EstadoPublicada - 1 abr 2018

Nota bibliográfica

Publisher Copyright:
© 2017 Elsevier B.V.

Huella

Profundice en los temas de investigación de 'Reduction of enthalpy relaxation in gelatine films by addition of polyols'. En conjunto forman una huella única.

Citar esto