INVESTIGADORES
RUSECKAITE Roxana Alejandra
artículos
Título:
Preparation and characterization of plasticized gelatin films cross-linked with low concentrations of glutaraldehyde
Autor/es:
MARTUCCI J.F.; ACCAREDDU A.; RUSECKAITE R.A
Revista:
JOURNAL OF MATERIALS SCIENCE
Editorial:
SPRINGER
Referencias:
Lugar: Berlin; Año: 2012 vol. 47 p. 2382 - 3292
ISSN:
0022-2461
Resumen:
Thermal and mechanical properties as well as
moisture resistance and water vapor barrier properties of
films from bovine gelatin added with D-sorbitol (30 wt%) as
plasticizer and cross-linked with low amounts of glutaraldehyde
(GTA, from 0 to 2 wt%) were investigated to
determine their suitability as barrier layers for flexible
packaging materials. Results revealed that free amino side
chain groups of gelatin decreased with GTA, confirming the
occurrence of cross-linking between GTA and gelatin. The
extent of cross-linking reaction in the presence of D-sorbitol
was lower compared with the unplasticized counterpart
suggesting that plasticizer hampers GTA to react. The glass
transition temperature (Tg) as measured from differential
scanning calorimetry (DSC) increased with GTA concentration
owing to the formation of more reticulated materials
while the incorporation of D-sorbitol led to a small reduction
in this parameter due to plasticization. Increasing GTA
concentration from 0 to 1 wt% provoked the enhancement of
elastic modulus from 3.7 ± 0.2 to 4.9 ± 0.2 GPa. These
values reduced significantly by the addition of D-sorbitol,
whereas elongation at break improved in about 150%. The
optimum formulation for the intended purpose was that
containing 1 wt% GTA and 30 wt% D-sorbitol since it
exhibited the best set of properties: total soluble mater
reduced from 100 to 16%, moisture absorption decreased
from 1854.1 ± 85 to 210.4 ± 8%, water vapor permeability
at 65% relative humidity improved from 2.42 ± 0.27
to 0.94 ± 0.06 9 10-14 kg m Pa-1 s-1 m-2, with minor reduction in opacity and with the additional benefit of
releasing only 5% of the initial GTA content.