Water and polymer dynamics in poly(hydroxyl ethyl acrylate-co-ethyl acrylate) copolymer hydrogels

Kyritsis, A; Spanoudaki, A; Pandis, C; Hartmann, L; Pelster, R; Shinyashiki, N; Rodriguez Hernandez, JC; Gomez Ribelles, JL; Monleon Pradas, M; Pissis, P

dc.contributor.author	Kyritsis, A	en
dc.contributor.author	Spanoudaki, A	en
dc.contributor.author	Pandis, C	en
dc.contributor.author	Hartmann, L	en
dc.contributor.author	Pelster, R	en
dc.contributor.author	Shinyashiki, N	en
dc.contributor.author	Rodriguez Hernandez, JC	en
dc.contributor.author	Gomez Ribelles, JL	en
dc.contributor.author	Monleon Pradas, M	en
dc.contributor.author	Pissis, P	en
dc.date.accessioned	2014-03-01T02:04:20Z
dc.date.available	2014-03-01T02:04:20Z
dc.date.issued	2011	en
dc.identifier.issn	00143057	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/29421
dc.subject	Decoupling	en
dc.subject	Dielectric spectroscopy	en
dc.subject	Glass transition	en
dc.subject	Poly(hydroxyethyl acrylate-co-ethyl acrylate) hydrogels	en
dc.subject	Segmental dynamics	en
dc.subject	Water sorption	en
dc.subject.other	Broadband dielectric relaxation spectroscopy	en
dc.subject.other	Copolymer compositions	en
dc.subject.other	Copolymer hydrogels	en
dc.subject.other	Copolymer matrix	en
dc.subject.other	Decoupling	en
dc.subject.other	Dielectric response	en
dc.subject.other	Dielectric strengths	en
dc.subject.other	Dielectric techniques	en
dc.subject.other	Equilibrium sorption isotherms	en
dc.subject.other	Ethyl acrylates	en
dc.subject.other	Hydration layers	en
dc.subject.other	Poly(ethyl acrylate)	en
dc.subject.other	Polymer dynamics	en
dc.subject.other	Random copolymer	en
dc.subject.other	Secondary relaxations	en
dc.subject.other	Segmental dynamics	en
dc.subject.other	Thermally stimulated depolarization currents	en
dc.subject.other	Time-scales	en
dc.subject.other	Water effects	en
dc.subject.other	Water molecule	en
dc.subject.other	Water sorption	en
dc.subject.other	Copolymers	en
dc.subject.other	Dielectric spectroscopy	en
dc.subject.other	Dynamics	en
dc.subject.other	Glass	en
dc.subject.other	Glass transition	en
dc.subject.other	Polymers	en
dc.subject.other	Sorption	en
dc.subject.other	Spectroscopy	en
dc.subject.other	Water content	en
dc.subject.other	Hydrogels	en
dc.title	Water and polymer dynamics in poly(hydroxyl ethyl acrylate-co-ethyl acrylate) copolymer hydrogels	en
heal.type	journalArticle	en
heal.identifier.primary	10.1016/j.eurpolymj.2011.09.025	en
heal.identifier.secondary	http://dx.doi.org/10.1016/j.eurpolymj.2011.09.025	en
heal.publicationDate	2011	en
heal.abstract	Water and polymer dynamics in hydrogels based on random copolymers of hydrophilic poly(hydroxyl ethyl acrylate) (PHEA) and hydrophobic poly(ethyl acrylate) (PEA), in wide ranges of composition, were investigated by means of two dielectric techniques, thermally stimulated depolarization currents (TSDC) and, mainly, broadband dielectric relaxation spectroscopy (DRS) at several levels of relative humidity/water content. Water sorption of the hydrogels was studied by equilibrium sorption isotherms (ESI). Two secondary relaxations (γ and βsw) and the primary (segmental) α relaxation associated with the glass transition of the copolymer matrix were followed and analyzed against copolymer composition and water content. The results show that the copolymers are homogeneous at nm scale, except at very high PEA content. Correlations were observed between results on the organization of water in the hydrogels and on water effects on polymer dynamics. Distinct changes in the dielectric response, in particular in the time scale and the dielectric strength of the βsw relaxation, at the water content of the completion of the first hydration layer indicate that water molecules themselves contribute to the dielectric response at higher water contents. Proton conductivity of the hydrogels at various levels of water content was also studied and correlation to segmental dynamics (decoupling) was analyzed. © 2011 Elsevier Ltd. All rights reserved.	en
heal.journalName	European Polymer Journal	en
dc.identifier.doi	10.1016/j.eurpolymj.2011.09.025	en
dc.identifier.volume	47	en
dc.identifier.issue	12	en
dc.identifier.spage	2391	en
dc.identifier.epage	2402	en