title: Toughening mechanisms in interfacially modified HDPE/thermoplastic starch blends.
abstract: The mechanical behavior of polymer blends containing 80 wt% of HDPE and 20 wt% of TPS and compatibilized with HDPE-g-MA grafted copolymer was investigated. Unmodified HDPE/TPS blends exhibit high fracture resistance, however, the interfacial modification of those blends by addition of HDPE-g-MA leads to a dramatic drop in fracture resistance. The compatibilization of HDPE/TPS blends increases the surface area of TPS particles by decreasing their size. It was postulated that the addition of HDPE-g-MA induces a reaction between maleic anhydride and hydroxyl groups of the glycerol leading to a decrease of the glycerol content in the TPS phase. This phenomenon increases the stiffness of the modified TPS particles and stiffer TPS particles leading to an important reduction in toughness and plastic deformation, as measured by the EWF method. It is shown that the main toughening mechanism in HDPE/TPS blends is shear-yielding. This article demonstrates that stiff, low diameter TPS particles reduce shear band formation and consequently decrease the resistance to crack propagation.
authors.affiliation: Centre des Matériaux des Mines d'Alès (C2MA), Ecole des Mines d'Alès (Institut Mines Télécom), 6 avenue de Clavières, F-30319 Alès Cedex, France; CREPEC, Department of Chemical Engineering, Ecole Polytechnique de Montréal, 2900 Bd Edouard Montpetit, PO 6079, Station Centre-Ville, Montréal, QC, Canada H3C 3A7. Electronic address: aurelie.taguet@mines-ales.fr.
authors.forename: Aurélie
authors.initials: A
authors.lastname: Taguet
authors.affiliation: Industrial Materials Institute, National Research Council Canada, 75 Bd de Mortagne, Boucherville, QC, Canada J4B 6Y4.
authors.forename: Martin N
authors.initials: MN
authors.lastname: Bureau
authors.affiliation: Industrial Materials Institute, National Research Council Canada, 75 Bd de Mortagne, Boucherville, QC, Canada J4B 6Y4.
authors.forename: Michel A
authors.initials: MA
authors.lastname: Huneault
authors.affiliation: CREPEC, Department of Chemical Engineering, Ecole Polytechnique de Montréal, 2900 Bd Edouard Montpetit, PO 6079, Station Centre-Ville, Montréal, QC, Canada H3C 3A7.
authors.forename: Basil D
authors.initials: BD
authors.lastname: Favis
keywords: Blends; Compatibilization; Glycerol; Starch; Toughness