Water absorbance and thermal properties of sulfated wheat gluten films

• Published in: Journal of applied polymer science 2010-06, Vol.116 (5), p.2638-2644
• Main Authors: Chiou, Bor-Sen, Robertson, George H., Rooff, LuAnn E., Cao, Trung, Jafri, Haani, Gregorski, Kay S., Imam, Syed H., Glenn, Greg M., Orts, William J.
• Format: Article
• Language: English
• Subjects: Applied sciences; biomaterials; Cold treatment; Deionization; Exact sciences and technology; Gluten; Natural polymers; Physicochemistry of polymers; Proteins; Reproduction; Solvents; Thermal properties; Thermal stability; Uptakes; Wheat
• ISSN: 0021-8995; 1097-4628; 1097-4628
• DOI: 10.1002/app.31778

Wheat gluten films of various thicknesses formed at 30–70°C were treated with cold sulfuric acid to produce sulfated gluten films. Chemical, thermal, thermal stability, and water uptake properties were characterized for neat and sulfated films. The sulfated gluten films were able to absorb up to 30 times their weight in deionized water. However, this value dropped to 3.5 when the film was soaked in a 0.9% (w/w) NaCl solution. The films were also soaked 4 times in deionized water, and each soaking resulted in a reduced water uptake capacity. The temperature of film formation had no effect on the final water uptake properties. Also, thinner films had higher concentrations of sulfate groups than thicker films; this resulted in higher water uptake values. In addition, sulfated gluten films had comparable glass‐transition temperatures but lower thermal stabilities than the neat gluten films. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010