0000000000535176

AUTHOR

R.e. Lechner

showing 3 related works from this author

QENS investigation of filled rubbers

2002

The polymer segmental dynamics is investigated in a series of silica-filled rubbers. The presence of inert fillers in polymers greatly affects the mechanical and physical performance of the final materials. For example, silica has been proposed as a reinforcing agent of elastomers in tire production. Results from quasielastic neutron scattering and Dynamic Mechanical Thermal Analysis (DMTA) measurements are presented on styrene–ran-butadiene rubber filled with silica. A clear indication is obtained of the existence of a bimodal dynamics, which can be rationalized in terms of the relaxation of bulk rubber and the much slower relaxation of the rubber adsorbed on the filler surface.

chemistry.chemical_classificationMaterials scienceGeneral ChemistryDynamic mechanical analysisPolymerengineering.materialElastomerNatural rubberchemistryvisual_artFiller (materials)Quasielastic neutron scatteringvisual_art.visual_art_mediumengineeringRelaxation (physics)General Materials ScienceComposite materialThermal analysisApplied Physics A: Materials Science & Processing
researchProduct

Structural and dynamical characterization of melt PEO–salt mixtures

2002

Abstract Salt doped poly ethylene oxide (PEO) mixtures were investigated by means of both small angle neutron scattering and QENS techniques aiming to characterize morphological and dynamical features in the melt state. These experimental evidences provide support to the proposed heterogeneous scenario for polymer electrolytes. In particular, the existence of PEO–cation complexes is proposed to play a major role in intramolecular cooperation and intermolecular transient crosslinks, which affects the mixture properties.

Statistics and Probabilitychemistry.chemical_classificationMaterials sciencePolymer electrolytesIntermolecular forceDopingtechnology industry and agricultureOxideSalt (chemistry)macromolecular substancesCondensed Matter PhysicsSmall-angle neutron scatteringCharacterization (materials science)chemistry.chemical_compoundchemistryChemical physicsIntramolecular forcePhysica A: Statistical Mechanics and its Applications
researchProduct

Segmental dynamics in polymer electrolytes

2002

Polymer dynamics in poly(ethylene oxide) (PEO)–salt mixtures is investigated by means of quasi-elastic neutron scattering (QENS). In a previous study, we reported QENS data from the NEAT spectrometer (BENSC) that evidenced, for the first time, a dynamic heterogeneity in PEO–salt mixtures induced by salt addition. This finding is supported by molecular dynamics (MD) simulations carried out by Borodin et al. In agreement with MD simulations, our QENS data revealed two distinct processes: a fast motion corresponding to the bulk polymer and a slower relaxation, which we attribute to formation of PEO–cation complexes. In this paper we present new QENS data from the high-resolution spectrometer I…

chemistry.chemical_classificationMaterials scienceEthylene oxideSpectrometerPolymer electrolytesDynamics (mechanics)Relaxation (NMR)General ChemistryPolymerNeutron scatteringCrystallographyMolecular dynamicschemistry.chemical_compoundchemistryChemical physicsGeneral Materials ScienceApplied Physics A: Materials Science & Processing
researchProduct