Polyvinyl Alcohol/Starch Films: Improvement of the Interactions, Migration Resistance, Thermal Stability, Gloss, and Biodegradability

ABSTRACT In this study, polyvinyl alcohol (PVOH)/starch (ST) films were obtained using sorbitol citrate (SC) to increase the interactions between PVOH and ST, the plasticization process, and to obtain films with low migration of the plasticizing agent. Furthermore, the impact of SC content on the properties of the PVOH/ST films was assessed. Migration degree (MD) values of the films were lower than 2.7% after 7 days of storage at 60°C. Infrared (IR) analysis revealed shifts in some signals (OH, CO, and CCO bonds) for the samples prepared with SC. The melting ( T m ) and glass transition ( T g ) temperatures of the PVOH/ST films were higher than those of the neat PVOH. CS increased the gloss, biodegradability, and thermal stability of the PVOH/ST films but decreased their opacity (OP). The maximum gloss value at 20° for the PVOH/ST films prepared with SC was 9.1 GU. All the films exhibited biodegradability between 55.28 and 70.28%. SC increased the interfacial adhesion of the PVOH/ST films. The elongation at break of the PVOH/ST films prepared with SC was higher (243–560%) than that of the films prepared without SC (227%).