Segmental relaxation of hydrophilic poly(vinylpyrrolidone) in chloroform studied by broadband dielectric spectroscopy

Shinyashiki, N; Spanoudaki, A; Yamamoto, W; Nambu, E; Yoneda, K; Kyritsis, A; Pissis, P; Kita, R; Yagihara, S

dc.contributor.author	Shinyashiki, N	en
dc.contributor.author	Spanoudaki, A	en
dc.contributor.author	Yamamoto, W	en
dc.contributor.author	Nambu, E	en
dc.contributor.author	Yoneda, K	en
dc.contributor.author	Kyritsis, A	en
dc.contributor.author	Pissis, P	en
dc.contributor.author	Kita, R	en
dc.contributor.author	Yagihara, S	en
dc.date.accessioned	2014-03-01T01:36:59Z
dc.date.available	2014-03-01T01:36:59Z
dc.date.issued	2011	en
dc.identifier.issn	0024-9297	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/21425
dc.subject.classification	Polymer Science	en
dc.subject.other	Arrhenius temperature	en
dc.subject.other	Asymmetric broadening	en
dc.subject.other	Broad-band dielectric spectroscopy	en
dc.subject.other	Chloroform solutions	en
dc.subject.other	Cooperativity	en
dc.subject.other	Hydrophilic polymers	en
dc.subject.other	Melting temperatures	en
dc.subject.other	Polyvinyl pyrrolidone	en
dc.subject.other	Repulsive forces	en
dc.subject.other	Segmental motion	en
dc.subject.other	Segmental relaxation	en
dc.subject.other	Small concentration	en
dc.subject.other	Time temperature superposition	en
dc.subject.other	Chlorine compounds	en
dc.subject.other	Hydrophilicity	en
dc.subject.other	Organic solvents	en
dc.title	Segmental relaxation of hydrophilic poly(vinylpyrrolidone) in chloroform studied by broadband dielectric spectroscopy	en
heal.type	journalArticle	en
heal.identifier.primary	10.1021/ma102394s	en
heal.identifier.secondary	http://dx.doi.org/10.1021/ma102394s	en
heal.language	English	en
heal.publicationDate	2011	en
heal.abstract	Dielectric relaxation caused by the segmental motion of poly(vinylpyrrolidone) (PVP) was studied in chloroform solutions with 5-40 wt % PVP at temperatures between 298 and 210 K above the melting temperature of chloroform (210 K) to obtain information on the dynamics of hydrophilic polymer. The asymmetric broadening of the loss peak and the fragility, i.e., the degree of deviation from the Arrhenius temperature dependence of relaxation time, increase with increasing PVP concentration. Both are due to increase in cooperativity of the segmental motion of PVP. The temperature-independent shape of the loss peak at a fixed concentration satisfies the time-temperature superposition and can be interpreted to be due to the small concentration fluctuation in the PVP/chloroform solutions. The repulsive force between PVP chains is expected to make the mixture homogeneous in chloroform, which is a good solvent of PVP. © 2011 American Chemical Society.	en
heal.publisher	AMER CHEMICAL SOC	en
heal.journalName	Macromolecules	en
dc.identifier.doi	10.1021/ma102394s	en
dc.identifier.isi	ISI:000289028500054	en
dc.identifier.volume	44	en
dc.identifier.issue	7	en
dc.identifier.spage	2140	en
dc.identifier.epage	2148	en