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Mean square displacement and reorientational correlation function in entangled polymer melts revealed by field cycling 1H and 2H NMR relaxometry

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dc.contributor.author Herrmann A.
dc.contributor.author Kresse B.
dc.contributor.author Wohlfahrt M.
dc.contributor.author Bauer I.
dc.contributor.author Privalov A.
dc.contributor.author Kruk D.
dc.contributor.author Fatkullin N.
dc.contributor.author Fujara F.
dc.contributor.author Rössler E.
dc.date.accessioned 2018-09-18T20:05:49Z
dc.date.available 2018-09-18T20:05:49Z
dc.date.issued 2012
dc.identifier.issn 0024-9297
dc.identifier.uri https://dspace.kpfu.ru/xmlui/handle/net/136462
dc.description.abstract Mixtures of protonated and deuterated polybutadiene and polydimethylsiloxane are studied by means of field-cycling (FC) 1H NMR relaxometry in order to analyze the intra- and intermolecular contributions to spin-lattice relaxation. They reflect reorientational and translational dynamics,respectively. Master curves in the susceptibility representation π″(ωτ s) are constructed by employing frequency-temperature superposition with τ s denoting the segmental correlation time. The intermolecular contribution is dominating at low frequencies and allows extracting the segmental mean square displacement 〈R 2(t)〉, which reveals two power-law regimes. The one at short times agrees with t 0.5 predicted for the free Rouse regime and at long times a lower exponent is observed in fair agreement with t 0.25 expected for the constrained Rouse regime of the tube-reptation model. Concomitantly the reorientational rank-two correlation function C 2(t/τ s) is obtained from the intramolecular part. Again two power-law regimes t -ε are identified for polybutadiene. The first agrees with t -1 of free Rouse dynamics whereas at long times ε = 0.49 is obtained. The latter is corroborated by the 2H relaxation of deuterated polybutadiene, yet, it does not agree with ε = 0.25 predicted for constrained Rouse dynamics. Thus, the relation C 2(t) ∝ 〈R 2(t)〉 -1 as assumed by the tube-reptation model is not confirmed. © 2012 American Chemical Society.
dc.relation.ispartofseries Macromolecules
dc.title Mean square displacement and reorientational correlation function in entangled polymer melts revealed by field cycling 1H and 2H NMR relaxometry
dc.type Article
dc.relation.ispartofseries-issue 16
dc.relation.ispartofseries-volume 45
dc.collection Публикации сотрудников КФУ
dc.relation.startpage 6516
dc.source.id SCOPUS00249297-2012-45-16-SID84865578975


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  • Публикации сотрудников КФУ Scopus [24551]
    Коллекция содержит публикации сотрудников Казанского федерального (до 2010 года Казанского государственного) университета, проиндексированные в БД Scopus, начиная с 1970г.

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