Molecular dynamics of poly (oxybutylene)s confined in pores of Vycor glass

Kyritsis, A

dc.contributor.author	Kyritsis, A	en
dc.date.accessioned	2014-03-01T01:26:42Z
dc.date.available	2014-03-01T01:26:42Z
dc.date.issued	2007	en
dc.identifier.issn	0022-3093	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/18178
dc.subject	36.20.r	en
dc.subject	64.70.Pf	en
dc.subject	77.22.Gm	en
dc.subject	Dielectric properties, relaxation, electric modulus	en
dc.subject	Glass transition	en
dc.subject	Polymers and organics	en
dc.subject.classification	Materials Science, Ceramics	en
dc.subject.classification	Materials Science, Multidisciplinary	en
dc.subject.other	Dielectric properties	en
dc.subject.other	Dielectric relaxation	en
dc.subject.other	Dielectric spectroscopy	en
dc.subject.other	Glass transition	en
dc.subject.other	Molecular dynamics	en
dc.subject.other	Electric modulus	en
dc.subject.other	Global chain motions	en
dc.subject.other	Relaxation dynamics	en
dc.subject.other	Vycor glass	en
dc.subject.other	Aromatic polymers	en
dc.title	Molecular dynamics of poly (oxybutylene)s confined in pores of Vycor glass	en
heal.type	journalArticle	en
heal.identifier.primary	10.1016/j.jnoncrysol.2007.02.071	en
heal.identifier.secondary	http://dx.doi.org/10.1016/j.jnoncrysol.2007.02.071	en
heal.language	English	en
heal.publicationDate	2007	en
heal.abstract	We have investigated the relaxation dynamics of poly (oxybutylene), POB, chains of various lengths, with different end groups (OH and CH3) in bulk and in confinement using dielectric relaxation spectroscopy. It is known that POB chains exhibit, apart from the segmental (main) relaxation process, the dielectric normal mode process which reflects the global chain motions. The comparative study of OH- and methyl-ended POB chains in bulk reveals the marked effect of association of hydroxyl end groups and indicates that the decrease in the density of the methylated specimens results in the acceleration of both relaxation processes, main and normal mode relaxations. For the confined POB chains the data indicate that the segmental relaxation process becomes faster (the effect being more pronounced for the methylated POB chains). A decrease in T-g of about 8 K for the methyl- and 2 K for OH-ended POB chains is estimated. Regarding the average relaxation rates of the normal mode process our data indicate that global chain mobility is not affected by the confinement. (c) 2007 Elsevier B.V. All rights reserved.	en
heal.publisher	ELSEVIER SCIENCE BV	en
heal.journalName	Journal of Non-Crystalline Solids	en
dc.identifier.doi	10.1016/j.jnoncrysol.2007.02.071	en
dc.identifier.isi	ISI:000251476300015	en
dc.identifier.volume	353	en
dc.identifier.issue	47-51	en
dc.identifier.spage	4318	en
dc.identifier.epage	4323	en