title: Shape memory starch-clay bionanocomposites.
abstract: 1-10% starch/clay bionanocomposites with shape memory properties were obtained by melt processing. X-ray diffraction (XRD) and TEM evidenced the presence of a major fraction of clay tactoids, consisting of 4-5 stacked crystalline layers, with a thickness of 6.8 nm. A significant orientation of the nanoparticles induced by extrusion was also observed. Tensile tests performed above the glass transition of the materials showed that the presence of clay nanoparticles leads to higher elastic modulus and maximum stress, without significant loss in elongation at break which typically reached 100%. Samples submitted to a 50% elongation and cooled below the glass transition showed shape memory behavior. Like unreinforced starch, the bionanocomposites showed complete shape recovery in unconstrained conditions. In mechanically constrained conditions, the maximum recovered stress was significantly improved for the bionanocomposites compared to unreinforced starch, opening promising perspectives for the design of sensors and actuators.
authors.affiliation: LUNAM Université, CNRS, GEPEA, UMR 6144, CRTT, 37, Boulevard de l'Université, 44606 St Nazaire Cedex, France; UR1268 Biopolymères Interactions Assemblages, INRA, F-44300 Nantes, France; Structure Fédérative IBSM, INRA Nantes-Angers, Rue de la Géraudière, BP 71627, 44316 Nantes Cedex 3, France. Electronic address: gildas.coativy@univ-nantes.fr.
authors.forename: Gildas
authors.initials: G
authors.lastname: Coativy
authors.affiliation: Institut des Matériaux Jean Rouxel (IMN), Université de Nantes-CNRS, UMR 6502, 2 rue de la Houssinière, BP 32229, 44322 Nantes Cedex, France. Electronic address: nicolas.gautier@cnrs-imn.fr.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Gautier
authors.affiliation: UR1268 Biopolymères Interactions Assemblages, INRA, F-44300 Nantes, France; Structure Fédérative IBSM, INRA Nantes-Angers, Rue de la Géraudière, BP 71627, 44316 Nantes Cedex 3, France. Electronic address: bruno.pontoire@nantes.inra.fr.
authors.forename: Bruno
authors.initials: B
authors.lastname: Pontoire
authors.affiliation: UR1268 Biopolymères Interactions Assemblages, INRA, F-44300 Nantes, France; Structure Fédérative IBSM, INRA Nantes-Angers, Rue de la Géraudière, BP 71627, 44316 Nantes Cedex 3, France. Electronic address: alain.buleon@nantes.inra.fr.
authors.forename: Alain
authors.initials: A
authors.lastname: Buléon
authors.affiliation: UR1268 Biopolymères Interactions Assemblages, INRA, F-44300 Nantes, France; Structure Fédérative IBSM, INRA Nantes-Angers, Rue de la Géraudière, BP 71627, 44316 Nantes Cedex 3, France. Electronic address: denis.lourdin@nantes.inra.fr.
authors.forename: Denis
authors.initials: D
authors.lastname: Lourdin
authors.affiliation: LUNAM Université, CNRS, GEPEA, UMR 6144, CRTT, 37, Boulevard de l'Université, 44606 St Nazaire Cedex, France; Structure Fédérative IBSM, INRA Nantes-Angers, Rue de la Géraudière, BP 71627, 44316 Nantes Cedex 3, France. Electronic address: eric.leroy@univ-nantes.fr.
authors.forename: Eric
authors.initials: E
authors.lastname: Leroy
mesh_terms: D001546:Bentonite / Q000737:chemistry*; D001672:Biocompatible Materials / Q000737:chemistry; D055119:Elastic Modulus; D046529:Microscopy, Electron, Transmission; D053761:Nanocomposites / Q000737:chemistry* / Q000648:ultrastructure; D013213:Starch / Q000737:chemistry*; D013718:Tensile Strength; D014961:X-Ray Diffraction
chemical_list: D001672:Biocompatible Materials; D001546:Bentonite; D013213:Starch
keywords: Bionanocomposite; Clay; Melt processing; Shape memory; Starch