Dielectric relaxation in copolymethacrylates containing side-chain nonlinear optical chromophores

Nikonorova, NA; Yakimansky, AV; Smirnov, NN; Kudryavtsev, VladislavV; Diaz-Calleja, R; Pissis, P

dc.contributor.author	Nikonorova, NA	en
dc.contributor.author	Yakimansky, AV	en
dc.contributor.author	Smirnov, NN	en
dc.contributor.author	Kudryavtsev, VladislavV	en
dc.contributor.author	Diaz-Calleja, R	en
dc.contributor.author	Pissis, P	en
dc.date.accessioned	2014-03-01T01:26:08Z
dc.date.available	2014-03-01T01:26:08Z
dc.date.issued	2007	en
dc.identifier.issn	0032-3861	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/17936
dc.subject	Dielectric relaxation	en
dc.subject	Nonlinear optical chromophores	en
dc.subject	Polymethacrylates	en
dc.subject.classification	Polymer Science	en
dc.subject.other	Copolymers	en
dc.subject.other	Dielectric relaxation	en
dc.subject.other	Electric fields	en
dc.subject.other	Glass transition	en
dc.subject.other	Molecular dynamics	en
dc.subject.other	Optimization	en
dc.subject.other	Thin films	en
dc.subject.other	Dielectric spectroscopy	en
dc.subject.other	Nonlinear optical chromophores	en
dc.subject.other	Polymethacrylates	en
dc.subject.other	Segmental mobility	en
dc.subject.other	Esters	en
dc.subject.other	copolymer	en
dc.subject.other	dielectric property	en
dc.subject.other	film	en
dc.subject.other	glass transition temperature	en
dc.subject.other	optical property	en
dc.subject.other	polyacrylate	en
dc.subject.other	relaxing	en
dc.title	Dielectric relaxation in copolymethacrylates containing side-chain nonlinear optical chromophores	en
heal.type	journalArticle	en
heal.identifier.primary	10.1016/j.polymer.2006.09.063	en
heal.identifier.secondary	http://dx.doi.org/10.1016/j.polymer.2006.09.063	en
heal.language	English	en
heal.publicationDate	2007	en
heal.abstract	Molecular mobility in the films of chromophore-containing copolymethacrylates was studied by dielectric spectroscopy. Near the glass transition temperature alpha- and beta-relaxation processes were observed, being related to segmental mobility and the reorientation of chromophore-containing side groups, respectively. It was shown that the temperature dependences of relaxation times in the range of the delta-process are linear or curvilinear for copolymers with 20 or 50% molar fraction of chromophore-containing units, indicating that the local or cooperative character of chromophore mobility was due to the absence (presence) of inter-chromophore interactions. These data are very important for optimizing the chromophore molar content in NLO polymers since the inter-chromophore dipole-dipole interactions usually lead to the formation of centrosymmetric anti-parallel aggregates which cannot be oriented by external electric fields. It was shown that the delta-process occurs at higher temperatures than the alpha-process. This fact is of great importance for optimizing the poling temperature at which macroscopic non-centrosymmetric orientation of chromophore occurs under the external electric field applied across a polymer film. The poling temperature should be at least not lower than the glass transition temperature for the delta-process. (c) 2006 Elsevier Ltd. All rights reserved.	en
heal.publisher	ELSEVIER SCI LTD	en
heal.journalName	Polymer	en
dc.identifier.doi	10.1016/j.polymer.2006.09.063	en
dc.identifier.isi	ISI:000243804100016	en
dc.identifier.volume	48	en
dc.identifier.issue	2	en
dc.identifier.spage	556	en
dc.identifier.epage	563	en