Polymer segmental dynamics and solvent thermal transitions in poly(ethyl acrylate)/p-xylene mixtures

Stathopoulos, AT; Kyritsis, A; Colomer, FJR; Ribelles, JLG; Shinyashiki, N; Christodoulides, C; Pissis, P

dc.contributor.author	Stathopoulos, AT	en
dc.contributor.author	Kyritsis, A	en
dc.contributor.author	Colomer, FJR	en
dc.contributor.author	Ribelles, JLG	en
dc.contributor.author	Shinyashiki, N	en
dc.contributor.author	Christodoulides, C	en
dc.contributor.author	Pissis, P	en
dc.date.accessioned	2014-03-01T01:36:39Z
dc.date.available	2014-03-01T01:36:39Z
dc.date.issued	2011	en
dc.identifier.issn	0887-6266	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/21381
dc.subject	differential scanning calorimetry (DSC)	en
dc.subject	glass transition	en
dc.subject	mixing	en
dc.subject	noncrystallized solvent	en
dc.subject	p-xylene	en
dc.subject	plasticization	en
dc.subject	poly (ethyl acrylate)	en
dc.subject	thermally stimulated depolarization currents	en
dc.subject.classification	Polymer Science	en
dc.subject.other	noncrystallized solvent	en
dc.subject.other	P-xylene	en
dc.subject.other	plasticization	en
dc.subject.other	poly (ethyl acrylate)	en
dc.subject.other	Thermally stimulated depolarization currents	en
dc.subject.other	Calorimeters	en
dc.subject.other	Concentration (process)	en
dc.subject.other	Crystallization	en
dc.subject.other	Depolarization	en
dc.subject.other	Differential scanning calorimetry	en
dc.subject.other	Gels	en
dc.subject.other	Glass	en
dc.subject.other	Glass transition	en
dc.subject.other	Mixtures	en
dc.subject.other	Optical communication	en
dc.subject.other	Polymers	en
dc.subject.other	Relaxation processes	en
dc.subject.other	Scanning	en
dc.subject.other	Solvents	en
dc.subject.other	Specific heat	en
dc.subject.other	Xylene	en
dc.subject.other	Aromatic hydrocarbons	en
dc.title	Polymer segmental dynamics and solvent thermal transitions in poly(ethyl acrylate)/p-xylene mixtures	en
heal.type	journalArticle	en
heal.identifier.primary	10.1002/polb.22185	en
heal.identifier.secondary	http://dx.doi.org/10.1002/polb.22185	en
heal.language	English	en
heal.publicationDate	2011	en
heal.abstract	A poly(ethyl acrylate) polymer network was swollen with different concentrations of the nonpolar solvent p-xylene, c(px), from xerogel until saturation (0 <= c(px) <= 0.85). Differential scanning calorimetry (DSC) and thermally stimulated depolarization currents (TSDC) techniques were employed to study the polymer segmental dynamics and the solvent thermal transitions in homogeneous (c(px) < 0.20) and partially crystallized (c(px) >= 0.20) PEA/p-xylene mixtures. Our DSC measurements indicate that p-xylene undergoes cold crystallization for intermediate solvent concentrations, 0.20 <= c(px) <= 0.30 while for higher c(px) values crystallization takes place during cooling. The results show that for c(px) <= 0.30 the T-g decreases with increasing c(px) (plasticization effect) obeying the respective Fox equation. For the same c(px) range we found that both the dielectric strength and the heat capacity increment of the segmental (alpha) relaxation process increase gradually with c(px) whereas the distribution of relaxation times for the underlying molecular relaxations does not change. For c(px) <= 0.30 the partially crystallized mixtures exhibit a constant Tg corresponding to the gel phase of PEA with an amount of p-xylene which is not able to crystallize under any conditions. The concentration of this noncrystallized p-xylene, c(UCpx), has been estimated to be between 0.12 and 0.15, independent of the total p-xylene concentration in the mixtures. When a separate p-xylene crystal phase is formed (for c(px) > 0.30) the segmental dielectric strength and heat capacity increment decrease significantly exhibiting values significantly lower than those measured for the homogeneous gels. In addition, we found that the presence of p-xylene crystals may induce marginal spatial heterogeneity of polymer (or p-xylene) concentration within the gel phase affecting thus slightly the breath of the segmental relaxation of PEA. We attribute these results to restrictions of polymer segmental configurations due to constraints imposed by the p-xylene crystals and/or to the immobilization of a part of the polymer chains. (C) 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 49: 455-466, 2011	en
heal.publisher	WILEY-BLACKWELL	en
heal.journalName	Journal of Polymer Science, Part B: Polymer Physics	en
dc.identifier.doi	10.1002/polb.22185	en
dc.identifier.isi	ISI:000288037700008	en
dc.identifier.volume	49	en
dc.identifier.issue	6	en
dc.identifier.spage	455	en
dc.identifier.epage	466	en