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Origin of toughness in .beta.-polypropylene: the effect of molecular mobility in the amorphous phase
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SYSNO ASEP 0440934 Druh ASEP J - Článek v odborném periodiku Zařazení RIV J - Článek v odborném periodiku Poddruh J Článek ve WOS Název Origin of toughness in .beta.-polypropylene: the effect of molecular mobility in the amorphous phase Tvůrce(i) Policianová, Olivia (UMCH-V) RID
Hodan, Jiří (UMCH-V)
Brus, Jiří (UMCH-V) RID, ORCID
Kotek, Jiří (UMCH-V) RIDZdroj.dok. Polymer. - : Elsevier - ISSN 0032-3861
Roč. 60, 9 March (2015), s. 107-114Poč.str. 8 s. Jazyk dok. eng - angličtina Země vyd. GB - Velká Británie Klíč. slova isotactic polypropylene ; β-modification ; toughness Vědní obor RIV JI - Kompozitní materiály CEP GA13-29009S GA ČR - Grantová agentura ČR Institucionální podpora UMCH-V - RVO:61389013 UT WOS 000351117300014 EID SCOPUS 84930487388 DOI 10.1016/j.polymer.2015.01.047 Anotace This study aims to explore the origin of toughness in β-phase isotactic polypropylene (i-PP). Samples of commercial-grade i-PP, both neat and nucleated with a specific β-nucleating agent (N,N′-dicyclohexylnaphthalene-2,6-dicarboxamide), were subjected to a combination of structure-sensitive methods and fracture mechanical testing. In addition to common structural characterisation methods, solid-state NMR data were collected to obtain information about the dynamics of the polymer segments as well as the structure. In particular, temperate-induced transformation between the free and constrained amorphous phase was monitored by variable-temperature 13C MAS NMR, whereas T1ρ(1H) relaxation was used to estimate correlations times of segmental motions. Lower thermodynamic stability of rigid amorphous fraction was found in the β-crystalline systems. In contrast helical chains in crystalline and constrained amorphous phase were found to be more restrained in the α-crystalline system. Overall, the results indicate larger restrictions in chain mobility in the amorphous phase of the α-polymorphic PP system than in that of the β-crystalline ones. Pracoviště Ústav makromolekulární chemie Kontakt Eva Čechová, cechova@imc.cas.cz ; Tel.: 296 809 358 Rok sběru 2016
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