High-strain-induced deformation mechanisms in block-graft and multigraft copolymers

Handle URI:
http://hdl.handle.net/10754/561954
Title:
High-strain-induced deformation mechanisms in block-graft and multigraft copolymers
Authors:
Schlegel, Ralf; Duan, Yongxin; Weidisch, Roland; Hölzer, Stefan M.; Schneider, Konrad M.; Stamm, Manfred; Uhrig, David W.; Mays, Jimmy Wayne; Heinrich, Gert; Hadjichristidis, Nikolaos ( 0000-0003-1442-1714 )
Abstract:
The molecular orientation behavior and structural changes of morphology at high strains for multigraft and block-graft copolymers based on polystyrene (PS) and polyisoprene (PI) were investigated during uniaxial monotonic loading via FT-IR and synchrotron SAXS. Results from FT-IR revealed specific orientations of PS and PI segments depending on molecular architecture and on the morphology, while structural investigations revealed a typical decrease in long-range order with increasing strain. This decrease was interpreted as strain-induced dissolution of the glassy blocks in the soft matrix, which is assumed to affect an additional enthalpic contribution (strain-induced mixing of polymer chains) and stronger retracting forces of the network chains during elongation. Our interpretation is supported by FT-IR measurements showing similar orientation of rubbery and glassy segments up to high strains. It also points to highly deformable PS domains. By synchrotron SAXS, we observed in the neo-Hookean region an approach of glassy domains, while at higher elongations the intensity of the primary reflection peak was significantly decreasing. The latter clearly verifies the assumption that the glassy chains are pulled out from the domains and are partly mixed in the PI matrix. Results obtained by applying models of rubber elasticity to stress-strain and hysteresis data revealed similar correlations between the softening behavior and molecular and morphological parameters. Further, an influence of the network modality was observed (random grafted branches). For sphere forming multigraft copolymers the domain functionality was found to be less important to achieve improved mechanical properties but rather size and distribution of the domains. © 2011 American Chemical Society.
KAUST Department:
Biological and Environmental Sciences and Engineering (BESE) Division; Physical Sciences and Engineering (PSE) Division; Chemical Science Program; KAUST Catalysis Center (KCC); Polymer Synthesis Laboratory
Publisher:
American Chemical Society
Journal:
Macromolecules
Issue Date:
13-Dec-2011
DOI:
10.1021/ma201353w
Type:
Article
ISSN:
00249297
Sponsors:
The authors thank for financial support of this work within the framework of the German Science Foundation (DFG) and Fraunhofer IWM Halle. A portion of this research at Oak Ridge National Laboratory's Center for Nanophase Materials Sciences was sponsored by the Scientific User Facilities Division, Office of Basic Energy Sciences, U.S. Department of Energy (enabled through User Project # 2003-028), and supported in part by the Division of Materials Science and Engineering, Office of Basic Energy Sciences, U.S. Department of Energy (DE- ACO5-00OR22725). Y. X. Duan thanks the support from Shang dong Province Science Fund (ZR2009AL011). We thank DESY for beamtime within the project II-20060086.
Appears in Collections:
Articles; Physical Sciences and Engineering (PSE) Division; Chemical Science Program; KAUST Catalysis Center (KCC); Biological and Environmental Sciences and Engineering (BESE) Division

Full metadata record

DC FieldValue Language
dc.contributor.authorSchlegel, Ralfen
dc.contributor.authorDuan, Yongxinen
dc.contributor.authorWeidisch, Rolanden
dc.contributor.authorHölzer, Stefan M.en
dc.contributor.authorSchneider, Konrad M.en
dc.contributor.authorStamm, Manfreden
dc.contributor.authorUhrig, David W.en
dc.contributor.authorMays, Jimmy Wayneen
dc.contributor.authorHeinrich, Gerten
dc.contributor.authorHadjichristidis, Nikolaosen
dc.date.accessioned2015-08-03T09:34:55Zen
dc.date.available2015-08-03T09:34:55Zen
dc.date.issued2011-12-13en
dc.identifier.issn00249297en
dc.identifier.doi10.1021/ma201353wen
dc.identifier.urihttp://hdl.handle.net/10754/561954en
dc.description.abstractThe molecular orientation behavior and structural changes of morphology at high strains for multigraft and block-graft copolymers based on polystyrene (PS) and polyisoprene (PI) were investigated during uniaxial monotonic loading via FT-IR and synchrotron SAXS. Results from FT-IR revealed specific orientations of PS and PI segments depending on molecular architecture and on the morphology, while structural investigations revealed a typical decrease in long-range order with increasing strain. This decrease was interpreted as strain-induced dissolution of the glassy blocks in the soft matrix, which is assumed to affect an additional enthalpic contribution (strain-induced mixing of polymer chains) and stronger retracting forces of the network chains during elongation. Our interpretation is supported by FT-IR measurements showing similar orientation of rubbery and glassy segments up to high strains. It also points to highly deformable PS domains. By synchrotron SAXS, we observed in the neo-Hookean region an approach of glassy domains, while at higher elongations the intensity of the primary reflection peak was significantly decreasing. The latter clearly verifies the assumption that the glassy chains are pulled out from the domains and are partly mixed in the PI matrix. Results obtained by applying models of rubber elasticity to stress-strain and hysteresis data revealed similar correlations between the softening behavior and molecular and morphological parameters. Further, an influence of the network modality was observed (random grafted branches). For sphere forming multigraft copolymers the domain functionality was found to be less important to achieve improved mechanical properties but rather size and distribution of the domains. © 2011 American Chemical Society.en
dc.description.sponsorshipThe authors thank for financial support of this work within the framework of the German Science Foundation (DFG) and Fraunhofer IWM Halle. A portion of this research at Oak Ridge National Laboratory's Center for Nanophase Materials Sciences was sponsored by the Scientific User Facilities Division, Office of Basic Energy Sciences, U.S. Department of Energy (enabled through User Project # 2003-028), and supported in part by the Division of Materials Science and Engineering, Office of Basic Energy Sciences, U.S. Department of Energy (DE- ACO5-00OR22725). Y. X. Duan thanks the support from Shang dong Province Science Fund (ZR2009AL011). We thank DESY for beamtime within the project II-20060086.en
dc.publisherAmerican Chemical Societyen
dc.titleHigh-strain-induced deformation mechanisms in block-graft and multigraft copolymersen
dc.typeArticleen
dc.contributor.departmentBiological and Environmental Sciences and Engineering (BESE) Divisionen
dc.contributor.departmentPhysical Sciences and Engineering (PSE) Divisionen
dc.contributor.departmentChemical Science Programen
dc.contributor.departmentKAUST Catalysis Center (KCC)en
dc.contributor.departmentPolymer Synthesis Laboratoryen
dc.identifier.journalMacromoleculesen
dc.contributor.institutionFraunhofer Institute for Mechanics of Materials IWM, D-06120 Halle, Germanyen
dc.contributor.institutionKey Laboratory of Rubber-Plastics (QUST), Ministry of Education, Qingdao University of Science and Technology, Zhenzhou Road, Qingdao 266042, Chinaen
dc.contributor.institutionInstitute of Chemistry, University of Halle, D-06099 Halle, Germanyen
dc.contributor.institutionLeibniz-Institut für Polymerforschung Dresden E.V., Hohe Strasse 6, D-01069 Dresden, Germanyen
dc.contributor.institutionCenter for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN 37831, United Statesen
dc.contributor.institutionDepartment of Chemistry, University of Tennessee, Knoxville, TN 37996, United Statesen
dc.contributor.institutionDepartment of Chemistry, University of Athens, Athens 157 71, Greeceen
kaust.authorHadjichristidis, Nikolaosen
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