title: Thermoplastic starch modified with microfibrillated cellulose and natural rubber latex: A broadband dielectric spectroscopy study.
abstract: Thermoplastic starch (TPS) biocomposites modified with cellulose microfibers and/or natural rubber were prepared via extrusion compounding. Glycerol and water served as plasticizers for starch. The dielectric properties of the TPS composites were examined via broadband dielectric spectroscopy in the temperature and frequency ranges of 30°C-65°C and 0.1Hz-10MHz, respectively. Each specimen was tested twice in order to study the effect of absorbed water. The hydrophobic/hydrophilic character of the modifiers governed the dielectric performance of the corresponding TPS biocomposites. Conducted analysis revealed two relaxation processes attributed to matrix-water-reinforcement interfacial polarization and glass to rubber transition of the TPS. Evaporation of water significantly affected the first process and only slightly the second one. Energy density, prior and after water evaporation, was also determined at constant field. By employing dielectric reinforcing function the contributions of water-assisted and constituents' originated interfacial phenomena could be separated.
authors.affiliation: Department of Materials Science, University of Patras, Patras 26504, Greece.
authors.forename: S X
authors.initials: SX
authors.lastname: Drakopoulos
authors.affiliation: Department of Polymer Engineering, Faculty of Mechanical Engineering, Budapest University of Technology and Economics, Műegyetem rkp. 3., H-1111 Budapest, Hungary,; MTA-BME Research Group for Composite Science and Technology, Műegyetem rkp. 3., H-1111 Budapest, Hungary.
authors.forename: J
authors.initials: J
authors.lastname: Karger-Kocsis
authors.affiliation: Department of Polymer Engineering, Faculty of Mechanical Engineering, Budapest University of Technology and Economics, Műegyetem rkp. 3., H-1111 Budapest, Hungary,; MTA-BME Research Group for Composite Science and Technology, Műegyetem rkp. 3., H-1111 Budapest, Hungary.
authors.forename: Á
authors.initials: Á
authors.lastname: Kmetty
authors.affiliation: Department of Polymer Engineering, Faculty of Mechanical Engineering, Budapest University of Technology and Economics, Műegyetem rkp. 3., H-1111 Budapest, Hungary.
authors.forename: L
authors.initials: L
authors.lastname: Lendvai
authors.affiliation: Department of Materials Science, University of Patras, Patras 26504, Greece. Electronic address: G.C.Psarras@upatras.gr.
authors.forename: G C
authors.initials: GC
authors.lastname: Psarras
mesh_terms: D002482:Cellulose / Q000737:chemistry*; D058266:Dielectric Spectroscopy; D007840:Latex / Q000737:chemistry*; D012408:Rubber / Q000737:chemistry*; D013213:Starch / Q000737:chemistry*
chemical_list: D007840:Latex; D002482:Cellulose; D013213:Starch; D012408:Rubber
keywords: Broadband dielectric spectroscopy; Microfibrillar cellulose; Natural rubber latex; Thermoplastic starch; Water effect