Thermal stability of PMMA-LDH nanocomposites: decoupling the physical barrier, radical trapping, and charring contributions using XAS/WAXS/Raman time-resolved experiments
Autor(a) principal: | |
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Data de Publicação: | 2018 |
Outros Autores: | , , , |
Tipo de documento: | Artigo |
Idioma: | eng |
Título da fonte: | Repositório Institucional da UNESP |
Texto Completo: | http://dx.doi.org/10.1039/C8RA07611A http://hdl.handle.net/11449/189808 |
Resumo: | In-depth understanding of the thermal stability of polymer-clay nanocomposites requires the use of advanced time-resolved techniques combined with multivariate data analysis, as well as the preparation of layered nanofillers with well-defined composition. The layered double hydroxide (LDH) compounds Zn2Al(OH)6·nH2O, Zn2Al0.75Fe0.25(OH)6·nH2O, ZnCuAl(OH)6·nH2O, and ZnCuAl0.5Fe0.5(OH)6·nH2O were prepared, each designed to specifically identify the physical barrier, radical trapping, and char formation contributions to the thermal stability of the PMMA-LDH nanocomposites. The unique combination of conventional methods (TG, DSC, and Raman spectroscopy) and synchrotron radiation techniques (XAS and WAXS), applied during PMMA-LDH heating, revealed the synergetic (of iron) and antagonist (of copper) effects of the LDH layers transformations on the three main endothermic steps of mass loss of the polymer. The diffusion barrier effect was proved by the downshift of the PMMA thermal decomposition temperature caused by the decrease of the LDH edifice thermostability when divalent cations were substituted in the LDH (passing from PMMA-Zn2Al(OH)6·nH2O to PMMA-ZnCuAl(OH)6·nH2O). For PMMA-Zn2Al0.75Fe0.25(OH)6·nH2O, a cooperative contribution of iron reduction, stabilisation of layered edifice, and radical trapping effects was observed for the thermal stability of the nanocomposite. LDH also acted as a diffusion barrier to the efflux and evaporation of depolymerized species, favouring the charring which exerts an additional contribution to thermal stability of the PMMA-LDH nanocomposites. |
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Repositório Institucional da UNESP |
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Thermal stability of PMMA-LDH nanocomposites: decoupling the physical barrier, radical trapping, and charring contributions using XAS/WAXS/Raman time-resolved experimentsIn-depth understanding of the thermal stability of polymer-clay nanocomposites requires the use of advanced time-resolved techniques combined with multivariate data analysis, as well as the preparation of layered nanofillers with well-defined composition. The layered double hydroxide (LDH) compounds Zn2Al(OH)6·nH2O, Zn2Al0.75Fe0.25(OH)6·nH2O, ZnCuAl(OH)6·nH2O, and ZnCuAl0.5Fe0.5(OH)6·nH2O were prepared, each designed to specifically identify the physical barrier, radical trapping, and char formation contributions to the thermal stability of the PMMA-LDH nanocomposites. The unique combination of conventional methods (TG, DSC, and Raman spectroscopy) and synchrotron radiation techniques (XAS and WAXS), applied during PMMA-LDH heating, revealed the synergetic (of iron) and antagonist (of copper) effects of the LDH layers transformations on the three main endothermic steps of mass loss of the polymer. The diffusion barrier effect was proved by the downshift of the PMMA thermal decomposition temperature caused by the decrease of the LDH edifice thermostability when divalent cations were substituted in the LDH (passing from PMMA-Zn2Al(OH)6·nH2O to PMMA-ZnCuAl(OH)6·nH2O). For PMMA-Zn2Al0.75Fe0.25(OH)6·nH2O, a cooperative contribution of iron reduction, stabilisation of layered edifice, and radical trapping effects was observed for the thermal stability of the nanocomposite. LDH also acted as a diffusion barrier to the efflux and evaporation of depolymerized species, favouring the charring which exerts an additional contribution to thermal stability of the PMMA-LDH nanocomposites.Universidade Estadual Paulista (UNESP) Instituto de Química, Rua Prof. Francisco Degni 55ICCF Université Clermont Auvergne UMR CNRS 6296 SIGMA Clermont, 24 av. des LandaisSynchrotron SOLEIL, L'Orme des Merisiers, Saint Aubin, BP48Universidade Estadual Paulista (UNESP) Instituto de Química, Rua Prof. Francisco Degni 55Universidade Estadual Paulista (Unesp)SIGMA ClermontSynchrotron SOLEILCarvalho, H. W.P. [UNESP]Leroux, F.Briois, V.Santilli, C. V. [UNESP]Pulcinelli, S. H. [UNESP]2019-10-06T16:52:48Z2019-10-06T16:52:48Z2018-01-01info:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/article34670-34681http://dx.doi.org/10.1039/C8RA07611ARSC Advances, v. 8, n. 60, p. 34670-34681, 2018.2046-2069http://hdl.handle.net/11449/18980810.1039/C8RA07611A2-s2.0-8505491896555842986818708650000-0002-8356-8093Scopusreponame:Repositório Institucional da UNESPinstname:Universidade Estadual Paulista (UNESP)instacron:UNESPengRSC Advancesinfo:eu-repo/semantics/openAccess2021-10-23T12:39:49Zoai:repositorio.unesp.br:11449/189808Repositório InstitucionalPUBhttp://repositorio.unesp.br/oai/requestopendoar:29462024-08-05T16:09:39.478647Repositório Institucional da UNESP - Universidade Estadual Paulista (UNESP)false |
dc.title.none.fl_str_mv |
Thermal stability of PMMA-LDH nanocomposites: decoupling the physical barrier, radical trapping, and charring contributions using XAS/WAXS/Raman time-resolved experiments |
title |
Thermal stability of PMMA-LDH nanocomposites: decoupling the physical barrier, radical trapping, and charring contributions using XAS/WAXS/Raman time-resolved experiments |
spellingShingle |
Thermal stability of PMMA-LDH nanocomposites: decoupling the physical barrier, radical trapping, and charring contributions using XAS/WAXS/Raman time-resolved experiments Carvalho, H. W.P. [UNESP] |
title_short |
Thermal stability of PMMA-LDH nanocomposites: decoupling the physical barrier, radical trapping, and charring contributions using XAS/WAXS/Raman time-resolved experiments |
title_full |
Thermal stability of PMMA-LDH nanocomposites: decoupling the physical barrier, radical trapping, and charring contributions using XAS/WAXS/Raman time-resolved experiments |
title_fullStr |
Thermal stability of PMMA-LDH nanocomposites: decoupling the physical barrier, radical trapping, and charring contributions using XAS/WAXS/Raman time-resolved experiments |
title_full_unstemmed |
Thermal stability of PMMA-LDH nanocomposites: decoupling the physical barrier, radical trapping, and charring contributions using XAS/WAXS/Raman time-resolved experiments |
title_sort |
Thermal stability of PMMA-LDH nanocomposites: decoupling the physical barrier, radical trapping, and charring contributions using XAS/WAXS/Raman time-resolved experiments |
author |
Carvalho, H. W.P. [UNESP] |
author_facet |
Carvalho, H. W.P. [UNESP] Leroux, F. Briois, V. Santilli, C. V. [UNESP] Pulcinelli, S. H. [UNESP] |
author_role |
author |
author2 |
Leroux, F. Briois, V. Santilli, C. V. [UNESP] Pulcinelli, S. H. [UNESP] |
author2_role |
author author author author |
dc.contributor.none.fl_str_mv |
Universidade Estadual Paulista (Unesp) SIGMA Clermont Synchrotron SOLEIL |
dc.contributor.author.fl_str_mv |
Carvalho, H. W.P. [UNESP] Leroux, F. Briois, V. Santilli, C. V. [UNESP] Pulcinelli, S. H. [UNESP] |
description |
In-depth understanding of the thermal stability of polymer-clay nanocomposites requires the use of advanced time-resolved techniques combined with multivariate data analysis, as well as the preparation of layered nanofillers with well-defined composition. The layered double hydroxide (LDH) compounds Zn2Al(OH)6·nH2O, Zn2Al0.75Fe0.25(OH)6·nH2O, ZnCuAl(OH)6·nH2O, and ZnCuAl0.5Fe0.5(OH)6·nH2O were prepared, each designed to specifically identify the physical barrier, radical trapping, and char formation contributions to the thermal stability of the PMMA-LDH nanocomposites. The unique combination of conventional methods (TG, DSC, and Raman spectroscopy) and synchrotron radiation techniques (XAS and WAXS), applied during PMMA-LDH heating, revealed the synergetic (of iron) and antagonist (of copper) effects of the LDH layers transformations on the three main endothermic steps of mass loss of the polymer. The diffusion barrier effect was proved by the downshift of the PMMA thermal decomposition temperature caused by the decrease of the LDH edifice thermostability when divalent cations were substituted in the LDH (passing from PMMA-Zn2Al(OH)6·nH2O to PMMA-ZnCuAl(OH)6·nH2O). For PMMA-Zn2Al0.75Fe0.25(OH)6·nH2O, a cooperative contribution of iron reduction, stabilisation of layered edifice, and radical trapping effects was observed for the thermal stability of the nanocomposite. LDH also acted as a diffusion barrier to the efflux and evaporation of depolymerized species, favouring the charring which exerts an additional contribution to thermal stability of the PMMA-LDH nanocomposites. |
publishDate |
2018 |
dc.date.none.fl_str_mv |
2018-01-01 2019-10-06T16:52:48Z 2019-10-06T16:52:48Z |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/article |
format |
article |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
http://dx.doi.org/10.1039/C8RA07611A RSC Advances, v. 8, n. 60, p. 34670-34681, 2018. 2046-2069 http://hdl.handle.net/11449/189808 10.1039/C8RA07611A 2-s2.0-85054918965 5584298681870865 0000-0002-8356-8093 |
url |
http://dx.doi.org/10.1039/C8RA07611A http://hdl.handle.net/11449/189808 |
identifier_str_mv |
RSC Advances, v. 8, n. 60, p. 34670-34681, 2018. 2046-2069 10.1039/C8RA07611A 2-s2.0-85054918965 5584298681870865 0000-0002-8356-8093 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.none.fl_str_mv |
RSC Advances |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
eu_rights_str_mv |
openAccess |
dc.format.none.fl_str_mv |
34670-34681 |
dc.source.none.fl_str_mv |
Scopus reponame:Repositório Institucional da UNESP instname:Universidade Estadual Paulista (UNESP) instacron:UNESP |
instname_str |
Universidade Estadual Paulista (UNESP) |
instacron_str |
UNESP |
institution |
UNESP |
reponame_str |
Repositório Institucional da UNESP |
collection |
Repositório Institucional da UNESP |
repository.name.fl_str_mv |
Repositório Institucional da UNESP - Universidade Estadual Paulista (UNESP) |
repository.mail.fl_str_mv |
|
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1808128612260380672 |