Počet záznamů: 1
In situ observation of nucleated polymer crystallization in polyoxymethylene sandwich composites
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SYSNO ASEP 0444199 Druh ASEP J - Článek v odborném periodiku Zařazení RIV J - Článek v odborném periodiku Poddruh J Článek ve WOS Název In situ observation of nucleated polymer crystallization in polyoxymethylene sandwich composites Tvůrce(i) Šlouf, Miroslav (UMCH-V) RID, ORCID
Krejčíková, Sabina (UMCH-V)
Vacková, Taťana (UMCH-V) RID
Kratochvíl, Jaroslav (UMCH-V) RID
Novák, L. (CZ)Zdroj.dok. Frontiers in Materials. - : Frontiers Media - ISSN 2296-8016
Roč. 2, 19 March (2015), 23_1-23_12Poč.str. 12 s. Jazyk dok. eng - angličtina Země vyd. CH - Švýcarsko Klíč. slova polyoxymethylene ; nucleated crystallization ; sandwich composites Vědní obor RIV JJ - Ostatní materiály CEP GAP205/10/0348 GA ČR - Grantová agentura ČR GA14-17921S GA ČR - Grantová agentura ČR TE01020118 GA TA ČR - Technologická agentura ČR Institucionální podpora UMCH-V - RVO:61389013 UT WOS 000218498500028 EID SCOPUS 85009711432 DOI 10.3389/fmats.2015.00023 Anotace We introduce a dynamic sandwich method, which can be used for in situ observation and quantification of polymer crystallization nucleated by micro/nanoparticles. The method was applied on polyoxymethylene (POM) composites with three nucleating agents: talc micropowder (POM/mTalc), chalk nanopowder (POM/nChalk), and titanate nanotubes (POM/TiNT). The nucleating agents were deposited between polymer films, the resulting sandwich samples were consolidated by thermal treatment, and their microtomed cross-sections were observed during isothermal crystallization by polarized light microscopy (PLM). As the intensity of polarized light was shown to be proportional to the relative crystallinity, the PLM results could be fitted to Avrami equation and the nucleating activity of all investigated particles could be quantified by means of Avrami parameters (n, k). The crystallization half-times increased reproducibly in the following order: POM/nChalk < POM/mTalc < POM/TiNT ~ POM. For strong nucleating agents (mTalc, nChalk), the crystallization kinetics corresponded to spontaneous crystallization starting from central nucleating layer, which was verified by computer simulations. The results were also confirmed by differential scanning calorimetry. We concluded that the sandwich method is an efficient microscopic technique for detailed evaluation of nucleating activity of arbitrary micro/nanoparticles in polymer systems. Pracoviště Ústav makromolekulární chemie Kontakt Eva Čechová, cechova@imc.cas.cz ; Tel.: 296 809 358 Rok sběru 2016
Počet záznamů: 1