Utilize este identificador para referenciar este registo:
https://hdl.handle.net/1822/12573
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Campo DC | Valor | Idioma |
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dc.contributor.author | Dencheva, Nadya Vasileva | - |
dc.contributor.author | Nunes, Teresa G. | - |
dc.contributor.author | Oliveira, M. J. | - |
dc.contributor.author | Denchev, Z. | - |
dc.date.accessioned | 2011-06-09T16:37:30Z | - |
dc.date.available | 2011-06-09T16:37:30Z | - |
dc.date.issued | 2005 | - |
dc.identifier.issn | 0887-6266 | por |
dc.identifier.issn | 1099-0488 | por |
dc.identifier.uri | https://hdl.handle.net/1822/12573 | - |
dc.description.abstract | The crystalline structure of polyamide-12 (PA12) was studied by solidstate 13C nuclear magnetic resonance (NMR) as well as by synchrotron wide- and small-angle X-ray scattering (WAXS and SAXS). Isotropic and oriented PA12 showed different NMR spectra ascribed to c- and c0-crystalline modifications, respectively. On the basis of the position of the first diffraction peak, the isotropic c-form and the oriented c0-form were shown to be with hexagonal crystalline lattice at room temperature. When heated, the two PA12 polymorphs demonstrated different behaviors. Above 140 8C, the isotropic c-PA12 partially transformed into a-modification. No such transition was observed with the oriented c0-PA12 phase even after annealing at temperatures close to melting. A c0–c transition was observed here only after isotropization by melting point. Various structural parameters were extracted from the WAXS and SAXS patterns and analyzed as a function of temperature and orientation: the degree of crystallinity, the d-spacings, the Bragg’s long spacings, the average thicknesses of the crystalline (lc) and amorphous (la) phases, and the linear crystallinity xcl within the lamellar stacks. | por |
dc.description.sponsorship | Fundação para a Ciência e a Tecnologia (FCT) - POCI/CTM/57358/2004, SFRH/BD/13435/2003 | por |
dc.language.iso | eng | por |
dc.publisher | Wiley | por |
dc.rights | restrictedAccess | por |
dc.subject | Annealing | por |
dc.subject | Crystallinity | por |
dc.subject | Polyamide 12 | por |
dc.subject | Solid-state NMR | por |
dc.subject | Synchrotron Xray scattering | por |
dc.title | Crystalline structure of polyamide 12 as revealed by solid-state 13C NMR and synchrotron WAXS and SAXS | por |
dc.type | article | - |
dc.peerreviewed | yes | por |
oaire.citationStartPage | 3720 | por |
oaire.citationEndPage | 3733 | por |
oaire.citationIssue | 24 | por |
oaire.citationTitle | Journal of Polymer Science Part B : Polymer Physics | por |
oaire.citationVolume | 43 | por |
dc.identifier.doi | 10.1002/polb.20672 | por |
dc.subject.wos | Science & Technology | por |
sdum.journal | Journal of Polymer Science Part B: Polymer Physics | por |
Aparece nas coleções: | IPC - Artigos em revistas científicas internacionais com arbitragem |
Ficheiros deste registo:
Ficheiro | Descrição | Tamanho | Formato | |
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9. Crystalline Structure of Polyamide 12 as Revealed by Solid-State 13C NMR and Synchrotron WAXS and SAXS.pdf Acesso restrito! | 515,5 kB | Adobe PDF | Ver/Abrir |