Effect of chemical treatment on the mechanical properties, water vapour permeability and sorption isotherms of gelatin-based films

• Published in: Packaging technology & science Vol. 21; no. 3; pp. 165 - 169
• Main Authors: Carvalho, R. A., Grosso, C. R. F., Sobral, P. J. A.
• Format: Journal Article
• Language: English
• Published: Chichester, UK John Wiley & Sons, Ltd 01.04.2008; Wiley
• Subjects: Applied sciences; cross-link; Exact sciences and technology; formaldehyde; glyoxal; Natural polymers; physical properties; Physicochemistry of polymers; protein; Proteins; physical properties; Transport properties; Mechanical properties; Crosslinking; Glyoxal; Experimental study; Property processing relationship; Modeling; Formaldehyde; Protein; Tensile strength; Chemical modification; Steam permeability; Gelatin; Crosslinked polymer; cross-link
• ISSN: 0894-3214; 1099-1522
• DOI: 10.1002/pts.792

Proteins contain hydrophilic groups, which can bind to water molecules through hydrogen bridges, resulting in water vapour adsorption. An increase in the degree of cross‐linking can be a method to improve the cohesiveness force and functional properties of protein‐based films. Thus, the objective of this work was to evaluate the effect of chemical treatment of gelatin with formaldehyde and glyoxal on the mechanical properties, water vapour permeability (WVP) and water vapour sorption characteristics of gelatin‐based films. Films were produced using gelatin, with and without chemical treatment. The formaldehyde treatments caused a significant increase in the tensile strength and a reduction in the WVP of films. The Guggenheim‐Anderson‐De Boer and Halsey models could be used to model the sorption isotherms of films. It was observed that an increase in temperature produced a decrease in water sorption, and the chemical modifications did not affect the monolayer moisture content. Copyright © 2007 John Wiley & Sons, Ltd.