Relationship between Nanostructure and Deformation Behavior of Microphase-Separated Styrene/Butadiene Systems

The relationship between the morphology and the mechanical properties of nanostructured blends,comprising an asymmetric styrene/butadiene star block copolymer,exhibiting cocontinuous-like morphology and low molar mass homopolymers, was studied by electron microscopy, microindentation hardness, and t...

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Detalles Bibliográficos
Autores: Adhikari, R., Lebek, Werner, Godehardt, Reinhold, Michler, G.H., Cagiao, M. E., Baltá Calleja, Francisco José, Knoll, Konrad
Tipo de recurso: artículo
Estado:Versión aceptada para publicación
Fecha de publicación:2006
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/79481
Acceso en línea:http://hdl.handle.net/10261/79481
Access Level:acceso abierto
Palabra clave:Block copolymers
Electron microscopy
Microhardness
Deformation behavior
Descripción
Sumario:The relationship between the morphology and the mechanical properties of nanostructured blends,comprising an asymmetric styrene/butadiene star block copolymer,exhibiting cocontinuous-like morphology and low molar mass homopolymers, was studied by electron microscopy, microindentation hardness, and tensile testing methods. Results show that the deformation behavior of these systems is significantly modified by the presence of unentangled homopolymer chains, leading partly to a decrease in mechanical properties. In contrast to common polymer blends, in which usually, the hardness values do not markedly deviate from the additivity law, the H-values in the system investigated show large deviations from the linear additivity behavior. The observed anomalous behavior is discussed in terms of the enhanced local flow processes induced by the phase-separated morphology at a nanometer scale.