Dependence of conformational relaxation on nanoconfinement in semicrystalline poly(ethylene terephthalate)

Novel aspects concerning the micromechanical response of amorphous regions confined by crystals in nano-sized domains are illustrated for semicrystalline poly(ethylene terephthalate) (PET), on the basis of microindentation hardness and dynamical mechanical spectroscopy (DMS) analyses (10-3÷60 Hz fre...

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Detalles Bibliográficos
Autores: Pieruccini, Marco, Flores, Araceli, Baltá Calleja, Francisco José
Tipo de recurso: artículo
Fecha de publicación:2013
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/89313
Acceso en línea:http://hdl.handle.net/10261/89313
Access Level:acceso abierto
Palabra clave:Cooperativity
Confinement
Relaxation
Mechanical spectroscopy
Semicrystalline polymers
Microhardness
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spelling Dependence of conformational relaxation on nanoconfinement in semicrystalline poly(ethylene terephthalate)Pieruccini, MarcoFlores, AraceliBaltá Calleja, Francisco JoséCooperativityConfinementRelaxationMechanical spectroscopySemicrystalline polymersMicrohardnessNovel aspects concerning the micromechanical response of amorphous regions confined by crystals in nano-sized domains are illustrated for semicrystalline poly(ethylene terephthalate) (PET), on the basis of microindentation hardness and dynamical mechanical spectroscopy (DMS) analyses (10-3÷60 Hz frequency range for DMS). PET samples were crystallized from the glassy state at low and high temperatures (Tc=100 C and 160 C, respectively) and subsequently recrystallized some degrees above to gain information on the nature of the amorphous regions. DMS at 95 C reveals two segmental relaxation processes ascribed to the interlamellar amorphous regions (slow mode) and to the interstack amorphous pockets (APs) (fast mode) respectively, the latter being the object of the present study. It is shown that recrystallization changes the cooperativity within the APs. At low Tc, an increase in the cooperativity and the free energy barrier for readjustment is found after recrystallization. Room temperature indentation measurements reveal an enhancement of the average hardness value of the amorphous regions, Ha, on samples recrystallized a few degrees above Tc=100 C. The reduced size of the APs regions upon recrystallization is discussed as a relevant parameter giving rise to an enhanced segmental confinement and a parallel hardening. Results for the high Tc material reveal that, in this case, both the cooperativity (measured at 95°C) and Ha (measured at room temperature) decrease upon recrystallization. The influence of the coupling of the APs with the crystal walls, on the relaxation mode and in turn on the mechanical behavior of the material, is envisaged to be a possible mechanism underlying these observations. © 2013 Elsevier Ltd. All rights reserved.Ministerio de Ciencia e Innovación Grant No. FIS2010-18069, Spain. MCYT, Spain, for the award of a sabbatical grant (SAB-2006-0077)Peer ReviewedElsevier2014201420132014info:eu-repo/semantics/articlehttp://purl.org/coar/resource_type/c_6501http://hdl.handle.net/10261/89313reponame:DIGITAL.CSIC. Repositorio Institucional del CSICinstname:Consejo Superior de Investigaciones Científicas (CSIC)Inglésinfo:eu-repo/semantics/openAccessoai:digital.csic.es:10261/893132026-05-22T06:33:51Z
dc.title.none.fl_str_mv Dependence of conformational relaxation on nanoconfinement in semicrystalline poly(ethylene terephthalate)
title Dependence of conformational relaxation on nanoconfinement in semicrystalline poly(ethylene terephthalate)
spellingShingle Dependence of conformational relaxation on nanoconfinement in semicrystalline poly(ethylene terephthalate)
Pieruccini, Marco
Cooperativity
Confinement
Relaxation
Mechanical spectroscopy
Semicrystalline polymers
Microhardness
title_short Dependence of conformational relaxation on nanoconfinement in semicrystalline poly(ethylene terephthalate)
title_full Dependence of conformational relaxation on nanoconfinement in semicrystalline poly(ethylene terephthalate)
title_fullStr Dependence of conformational relaxation on nanoconfinement in semicrystalline poly(ethylene terephthalate)
title_full_unstemmed Dependence of conformational relaxation on nanoconfinement in semicrystalline poly(ethylene terephthalate)
title_sort Dependence of conformational relaxation on nanoconfinement in semicrystalline poly(ethylene terephthalate)
dc.creator.none.fl_str_mv Pieruccini, Marco
Flores, Araceli
Baltá Calleja, Francisco José
author Pieruccini, Marco
author_facet Pieruccini, Marco
Flores, Araceli
Baltá Calleja, Francisco José
author_role author
author2 Flores, Araceli
Baltá Calleja, Francisco José
author2_role author
author
dc.subject.none.fl_str_mv Cooperativity
Confinement
Relaxation
Mechanical spectroscopy
Semicrystalline polymers
Microhardness
topic Cooperativity
Confinement
Relaxation
Mechanical spectroscopy
Semicrystalline polymers
Microhardness
description Novel aspects concerning the micromechanical response of amorphous regions confined by crystals in nano-sized domains are illustrated for semicrystalline poly(ethylene terephthalate) (PET), on the basis of microindentation hardness and dynamical mechanical spectroscopy (DMS) analyses (10-3÷60 Hz frequency range for DMS). PET samples were crystallized from the glassy state at low and high temperatures (Tc=100 C and 160 C, respectively) and subsequently recrystallized some degrees above to gain information on the nature of the amorphous regions. DMS at 95 C reveals two segmental relaxation processes ascribed to the interlamellar amorphous regions (slow mode) and to the interstack amorphous pockets (APs) (fast mode) respectively, the latter being the object of the present study. It is shown that recrystallization changes the cooperativity within the APs. At low Tc, an increase in the cooperativity and the free energy barrier for readjustment is found after recrystallization. Room temperature indentation measurements reveal an enhancement of the average hardness value of the amorphous regions, Ha, on samples recrystallized a few degrees above Tc=100 C. The reduced size of the APs regions upon recrystallization is discussed as a relevant parameter giving rise to an enhanced segmental confinement and a parallel hardening. Results for the high Tc material reveal that, in this case, both the cooperativity (measured at 95°C) and Ha (measured at room temperature) decrease upon recrystallization. The influence of the coupling of the APs with the crystal walls, on the relaxation mode and in turn on the mechanical behavior of the material, is envisaged to be a possible mechanism underlying these observations. © 2013 Elsevier Ltd. All rights reserved.
publishDate 2013
dc.date.none.fl_str_mv 2013
2014
2014
2014
dc.type.none.fl_str_mv info:eu-repo/semantics/article
http://purl.org/coar/resource_type/c_6501
format article
dc.identifier.none.fl_str_mv http://hdl.handle.net/10261/89313
url http://hdl.handle.net/10261/89313
dc.language.none.fl_str_mv Inglés
language_invalid_str_mv Inglés
dc.rights.none.fl_str_mv info:eu-repo/semantics/openAccess
eu_rights_str_mv openAccess
dc.publisher.none.fl_str_mv Elsevier
publisher.none.fl_str_mv Elsevier
dc.source.none.fl_str_mv reponame:DIGITAL.CSIC. Repositorio Institucional del CSIC
instname:Consejo Superior de Investigaciones Científicas (CSIC)
instname_str Consejo Superior de Investigaciones Científicas (CSIC)
reponame_str DIGITAL.CSIC. Repositorio Institucional del CSIC
collection DIGITAL.CSIC. Repositorio Institucional del CSIC
repository.name.fl_str_mv
repository.mail.fl_str_mv
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