title: Structure and physical properties of starch/poly vinyl alcohol/sodium montmorillonite nanocomposite films.
abstract: Nanocomposites of starch, poly vinyl alcohol (PVOH), and sodium montmorillonite (Na(+)MMT) were produced by solution mixing and cast into films. Tensile strength (TS) and elongation at the break (E%) of the films ranged from 11.60 to 22.35 MPa and 28.93-211.40%, respectively, while water vapor permeability (WVP) ranged from 0.718 to 1.430 g·mm/kPa·h·m(2). In general, an increase in Na(+)MMT content (0-20%) enhanced TS and decreased E% and WVP. Use of higher molecular weight PVOH increased both TS and E% and also decreased WVP. Mechanical properties were negatively affected, but water vapor barrier properties improved with increasing starch content (0-80%). X-ray diffraction and transmission electron microscopy were used to analyze the nanostructure, and molecular conformations and interactions in the multicomponent nanocomposites were inferred from glass transition behavior. Interactions between starch and PVOH were strongest, followed by polymer/clay interactions. On the basis of this insight, a conceptual model was presented to explain the phenomena of intercalation and exfoliation in the starch/PVOH/Na(+)MMT nanocomposites.
authors.affiliation: Department of Grain Science and Industry, Kansas State University, 201 Shellenberger Hall, Manhattan, Kansas 66506, United States.
authors.forename: Samer S
authors.initials: SS
authors.lastname: Ali
authors.forename: Xiaozhi
authors.initials: X
authors.lastname: Tang
authors.forename: Sajid
authors.initials: S
authors.lastname: Alavi
authors.forename: Jon
authors.initials: J
authors.lastname: Faubion
mesh_terms: D001546:Bentonite / Q000737:chemistry*; D055598:Chemical Phenomena; D018857:Food Packaging / Q000295:instrumentation*; D053761:Nanocomposites / Q000737:chemistry*; D010539:Permeability; D011142:Polyvinyl Alcohol / Q000737:chemistry*; D013213:Starch / Q000737:chemistry*; D013227:Steam; D013718:Tensile Strength
chemical_list: D013227:Steam; D001546:Bentonite; D011142:Polyvinyl Alcohol; D013213:Starch