title: Fundamental limits of material toughening in molecularly confined polymers.
abstract: The exceptional mechanical properties of polymer nanocomposites are achieved through intimate mixing of the polymer and inorganic phases, which leads to spatial confinement of the polymer phase. In this study we probe the mechanical and fracture properties of polymers in the extreme limits of molecular confinement, where a stiff inorganic phase confines the polymer chains to dimensions far smaller than their bulk radius of gyration. We show that polymers confined at molecular length scales dissipate energy through a confinement-induced molecular bridging mechanism that is distinct from existing entanglement-based theories of polymer deformation and fracture. We demonstrate that the toughening is controlled by the molecular size and the degree of confinement, but is ultimately limited by the strength of individual molecules.
authors.affiliation: Department of Materials Science and Engineering, Stanford University, 496 Lomita Mall, Stanford, California 94305, USA.
authors.forename: Scott G
authors.initials: SG
authors.lastname: Isaacson
authors.affiliation: Hybrid Polymeric Materials, IBM Almaden Research Center, 650 Harry Road, San Jose, California 95120-6099, USA.
authors.forename: Krystelle
authors.initials: K
authors.lastname: Lionti
authors.affiliation: Hybrid Polymeric Materials, IBM Almaden Research Center, 650 Harry Road, San Jose, California 95120-6099, USA.
authors.forename: Willi
authors.initials: W
authors.lastname: Volksen
authors.affiliation: Hybrid Polymeric Materials, IBM Almaden Research Center, 650 Harry Road, San Jose, California 95120-6099, USA.
authors.forename: Teddie P
authors.initials: TP
authors.lastname: Magbitang
authors.affiliation: Department of Materials Science and Engineering, Stanford University, 496 Lomita Mall, Stanford, California 94305, USA.
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Matsuda
authors.affiliation: Department of Materials Science and Engineering, Stanford University, 496 Lomita Mall, Stanford, California 94305, USA.
authors.forename: Reinhold H
authors.initials: RH
authors.lastname: Dauskardt
authors.affiliation: Department of Materials Science and Engineering, Stanford University, 496 Lomita Mall, Stanford, California 94305, USA.|Hybrid Polymeric Materials, IBM Almaden Research Center, 650 Harry Road, San Jose, California 95120-6099, USA.
authors.forename: Geraud
authors.initials: G
authors.lastname: Dubois
mesh_terms: D008422:Materials Testing / Q000379:methods*; D053761:Nanocomposites / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry*
chemical_list: D011108:Polymers