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Gas barrier changes and morphological alterations induced by retorting in ethylene vinyl alcohol–based food packaging structures
Author(s) -
LópezRubio Amparo,
HernándezMuñoz Pilar,
Gimenez Enrique,
Yamamoto Tomoyuki,
Gavara Rafael,
Lagarón Jose M.
Publication year - 2005
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.21690
Subject(s) - ethylene , crystallinity , copolymer , vinyl alcohol , materials science , chemical engineering , retort , sorption , polymer , food packaging , polymer chemistry , chemistry , composite material , organic chemistry , catalysis , adsorption , food science , engineering
Ethylene vinyl alcohol (EVOH)–based packaging structures were analyzed in terms of both barrier properties and morphological alterations after a retorting process and as functions of ethylene content. From the results, it was found that the samples do have a substantial decrease in oxygen barrier properties and that the kinetics of recovery strongly depends on the copolymer ethylene fraction. A morphological deterioration was also observed as a result of retorting, particularly for packaging structures composed of EVOH copolymers of low ethylene contents. However, the polymer morphology and barrier properties were restored after a dry thermal treatment of the retorted samples. Interestingly, preannealing of copolymers of low ethylene content rendered them more resistant to the retorting process by means of promoting both a more robust crystallinity and a lower water sorption capacity. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 2192–2202, 2005