Properties of starch-based blend films using citric acid as additive. II

Starch/polyvinyl alcohol (PVA) blend films were prepared by using corn starch, polyvinyl alcohol (PVA), glycerol (CL), and citric acid (CA) as additives and glutaraldehyde (GLU) as crosslinking agent for the mixing process. The additives, drying temperature, and the influence of crosslinker of films on the properties of the films were investigated. The mechanical properties, tensile strength (TS), elongation at break (% E), degree of swelling (DS), and solubility (S) of starch/PVA blend film were examined adding GL and CA as additives. At all measurement results, except for DS, the film adding CA was better than GL because hydrogen bonding at the presence of CA with hydroxyl group and carboxyl group increased the inter/intramolecular interaction between starch, PVA, and additives. CA improves the properties of starch/PVA blend film compared with GL. TS, %, E, DS, and S of film adding GLU as crosslinking agent were examined. With increasing GLU contents, TS increases but % E, DS, and S value of GL-added and CA-added films decrease. When the film was dried at low temperature, the physical properties of the films were clearly improved because the hydrogen bonding was activated at low temperature. (c) 2006 Wiley Periodicals, Inc.