Preparation and characterization of acetylated corn starch-(PVOH)/clay nanocomposite films.

Acetylated corn starch (ACS)-based clay (NaMMT) nanocomposite films, with or without addition of polyvinyl alcohol (PVOH), were prepared by casting with glycerol as a plasticizer. The obtained nanocomposite structure was ascertained by XRD study for all polymer-clay nanocomposites. XRD patterns are indicative of an intercalated nanocomposite structure. Mechanical and thermomechanical properties of polymer nanocomposites were studied. The addition of clay induces significant reinforcing effects in the thermoplastic ACS systems. Replacement of glycerol with PVOH in the ACS-NaMMT system results in superior mechanical strength, due to the creation of hydrogen bonds between the ACS and the PVOH chains. Enhancement in water barrier properties was observed for all nanocomposite films, which reaches up to 67% for acetylated starch-PVOH-clay nanocomposites in comparison to acetylated thermoplastic starch, as indicated by water vapor transmission measurements.