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The water vapor sorption behavior of a galactomannan cellulose nanocomposite film analyzed using parallel exponential kinetics and the Kelvin–Voigt viscoelastic model
Author(s) -
Keating Barbara A.,
Hill Callum A. S.,
Sun Dongyang,
English Rob,
Davies Phil,
McCue Charles
Publication year - 2013
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.39132
Subject(s) - sorption , materials science , guar , nanocomposite , viscoelasticity , desorption , guar gum , composite material , chemical engineering , adsorption , polymer chemistry , chemistry , organic chemistry , biochemistry , engineering
Abstract Nanocomposite films have been developed where a galactomannan (guar) matrix was reinforced with cellulose nanowhiskers and plasticized using sorbitol. The properties of these films were compared with films made from guar only. The films were examined using scanning electron microscopy and dynamic vapor sorption. The sorption kinetics properties were analyzed using parallel exponential kinetics (PEK) and this data interpreted using the Kelvin‐Voigt (K‐V) viscoelastic model. Substantial differences in sorption behavior were noted between the guar and cellulose reinforced guar films. Addition of cellulose nanowhiskers (CNWs) to the guar resulted in a change in the shape of the isotherm, as well as a reduced equilibrium moisture content throughout the hygroscopic range. With the guar film, hysteresis between the adsorption and desorption branches of the isotherm occurred up to 75% RH, where it collapsed. Dynamic mechanical analysis showed that the collapse of the hysteresis loop occurred at the glass transition temperature of the guar film. However, addition of CNWs to the guar produced a film where sorption hysteresis was found to occur throughout the hygroscopic range. The applicability of the K‐V interpretation of the sorption kinetics is discussed. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013