Glass transition and polymer dynamics in silver/poly(methyl methacrylate) nanocomposites

Pandis, C; Logakis, E; Kyritsis, A; Pissis, P; Vodnik, VV; Dzunuzovic, E; Nedeljkovic, JM; Djokovic, V; Rodriguez Hernandez, JC; Gomez Ribelles, JL

dc.contributor.author	Pandis, C	en
dc.contributor.author	Logakis, E	en
dc.contributor.author	Kyritsis, A	en
dc.contributor.author	Pissis, P	en
dc.contributor.author	Vodnik, VV	en
dc.contributor.author	Dzunuzovic, E	en
dc.contributor.author	Nedeljkovic, JM	en
dc.contributor.author	Djokovic, V	en
dc.contributor.author	Rodriguez Hernandez, JC	en
dc.contributor.author	Gomez Ribelles, JL	en
dc.date.accessioned	2014-03-01T01:35:46Z
dc.date.available	2014-03-01T01:35:46Z
dc.date.issued	2011	en
dc.identifier.issn	0014-3057	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/21185
dc.subject	Ag nanoparticles	en
dc.subject	Free volume	en
dc.subject	Glass transition	en
dc.subject	Polymer dynamics	en
dc.subject	Segmental relaxation	en
dc.subject.classification	Polymer Science	en
dc.subject.other	Ag nanoparticle	en
dc.subject.other	Broadband dielectric relaxation spectroscopy	en
dc.subject.other	Filler contents	en
dc.subject.other	Good correlations	en
dc.subject.other	Mean diameter	en
dc.subject.other	Methyl methacrylates	en
dc.subject.other	Oleylamine	en
dc.subject.other	PMMA matrices	en
dc.subject.other	Polymer dynamics	en
dc.subject.other	Polymer-filler- Interaction	en
dc.subject.other	Rubbery state	en
dc.subject.other	Segmental relaxation	en
dc.subject.other	Surface-modified	en
dc.subject.other	Thermally stimulated depolarization currents	en
dc.subject.other	Time-scales	en
dc.subject.other	Acrylic monomers	en
dc.subject.other	Differential scanning calorimetry	en
dc.subject.other	Dynamic mechanical analysis	en
dc.subject.other	Esters	en
dc.subject.other	Filled polymers	en
dc.subject.other	Fillers	en
dc.subject.other	Free radical polymerization	en
dc.subject.other	Glass	en
dc.subject.other	Nanocomposites	en
dc.subject.other	Nanoparticles	en
dc.subject.other	Polymers	en
dc.subject.other	Silver	en
dc.subject.other	Spectroscopy	en
dc.subject.other	Thermoanalysis	en
dc.subject.other	Glass transition	en
dc.title	Glass transition and polymer dynamics in silver/poly(methyl methacrylate) nanocomposites	en
heal.type	journalArticle	en
heal.identifier.primary	10.1016/j.eurpolymj.2011.06.001	en
heal.identifier.secondary	http://dx.doi.org/10.1016/j.eurpolymj.2011.06.001	en
heal.language	English	en
heal.publicationDate	2011	en
heal.abstract	Dynamic mechanical-thermal analysis (DMTA), differential scanning calorimetry (DSC), thermally stimulated depolarization currents (TSDC) and, mainly, broadband dielectric relaxation spectroscopy (DRS) were employed to investigate in detail glass transition and polymer dynamics in silver/poly(methyl methacrylate) (Ag/PMMA) nanocomposites. The nanocomposites were prepared by radical polymerization of MMA in the presence of surface modified Ag nanoparticles with a mean diameter of 5.6 nm dispersed in chloroform. The fraction of Ag nanoparticles in the final materials was varied between 0 and 0.5 wt%, the latter corresponding to 0.055 vol%. The results show that the nanoparticles have practically no effect on the time scale of the secondary beta and gamma relaxations, whereas the magnitude of both increases slightly but systematically with increasing filler content. The segmental alpha relaxation, associated with the glass transition, becomes systematically faster and stronger in the nanocomposites. The glass transition temperature T-g decreases with increasing filler content of the nanocomposites up to about 10 degrees C. in good correlation by the four techniques employed. Finally, the elastic modulus decreases slightly but systematically in the nanocomposites, both in the glassy and in the rubbery state. The results are explained in terms of plasticization of the PMMA matrix, due to constraints imposed to packing of the chains by the Ag nanoparticles, and, at the same time, of the absence of strong polymer-filler interactions, due to the surface modification of the Ag nanoparticles by oleylamine at the stage of preparation. (C) 2011 Elsevier Ltd. All rights reserved.	en
heal.publisher	PERGAMON-ELSEVIER SCIENCE LTD	en
heal.journalName	European Polymer Journal	en
dc.identifier.doi	10.1016/j.eurpolymj.2011.06.001	en
dc.identifier.isi	ISI:000293939800003	en
dc.identifier.volume	47	en
dc.identifier.issue	8	en
dc.identifier.spage	1514	en
dc.identifier.epage	1525	en