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International Journal of Polymer Science
Volume 2012 (2012), Article ID 482810, 8 pages
http://dx.doi.org/10.1155/2012/482810
Research Article

Films from Glyoxal-Crosslinked Spruce Galactoglucomannans Plasticized with Sorbitol

1Department of Food and Environmental Sciences, University of Helsinki, P.O. Box 27, 00014 Helsinki, Finland
2Process Chemistry Centre, Åbo Akademi University, Porthansgatan 3, 20500 Åbo, Finland

Received 23 June 2011; Revised 22 September 2011; Accepted 3 October 2011

Academic Editor: Annamaria Celli

Copyright © 2012 Kirsi S. Mikkonen et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Films were prepared from a renewable and biodegradable forest biorefinery product, spruce O-acetyl-galactoglucomannans (GGMs), crosslinked with glyoxal. For the first time, cohesive and self-standing films were obtained from GGM without the addition of polyol plasticizer. In addition, glyoxal-crosslinked films were prepared using sorbitol at 10, 20, 30, and 40% (wt.-% of GGM). Glyoxal clearly strengthened the GGM matrix, as detected by tensile testing and dynamic mechanical analysis. The elongation at break of films slightly increased, and Young's modulus decreased with increasing sorbitol content. Interestingly, the tensile strength of films was constant with the increased plasticizer content. The effect of sorbitol on water sorption and water vapor permeability (WVP) depended on relative humidity (RH). At low RH, the addition of sorbitol significantly decreased the WVP of films. The glyoxal-crosslinked GGM films containing 20% sorbitol exhibited the lowest oxygen permeability (OP) and WVP of the studied films and showed satisfactory mechanical performance.