Relaxation spectrum of polymer networks formed from butyl acrylate and methyl methacrylate monomeric units

Berzosa, AE; Ribelles, JLG; Kripotou, S; Pissis, P

dc.contributor.author	Berzosa, AE	en
dc.contributor.author	Ribelles, JLG	en
dc.contributor.author	Kripotou, S	en
dc.contributor.author	Pissis, P	en
dc.date.accessioned	2014-03-01T01:21:18Z
dc.date.available	2014-03-01T01:21:18Z
dc.date.issued	2004	en
dc.identifier.issn	0024-9297	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/16190
dc.subject	Spectrum	en
dc.subject	Butyl Acrylate	en
dc.subject.classification	Polymer Science	en
dc.subject.other	Dielectric relaxation spectroscopy	en
dc.subject.other	Molecular mobility	en
dc.subject.other	Thermally stimulated depolarization currents (TSDC)	en
dc.subject.other	Copolymers	en
dc.subject.other	Crosslinking	en
dc.subject.other	Dielectric relaxation	en
dc.subject.other	Dynamic mechanical analysis	en
dc.subject.other	Frequency domain analysis	en
dc.subject.other	Glass transition	en
dc.subject.other	Monomers	en
dc.subject.other	Polarization	en
dc.subject.other	Polyacrylates	en
dc.subject.other	Polymethyl methacrylates	en
dc.subject.other	Thermal effects	en
dc.subject.other	Interpenetrating polymer networks	en
dc.title	Relaxation spectrum of polymer networks formed from butyl acrylate and methyl methacrylate monomeric units	en
heal.type	journalArticle	en
heal.identifier.primary	10.1021/ma049429r	en
heal.identifier.secondary	http://dx.doi.org/10.1021/ma049429r	en
heal.language	English	en
heal.publicationDate	2004	en
heal.abstract	The aim of this work is to study the merging of the main alpha and the secondary beta relaxations in poly(butyl acrylate)-i-poly(methyl methacrylate) sequential interpenetrating networks in comparison to net-poly(butyl acrylate)-co-poly(methyl methacrylate) random copolymer networks. In both cases 10% of ethylene glycol dimethacrylate was used as cross-linking agent. The cross-linking density of these networks is high enough to force a certain degree of compatibility of the IPNs, as shown by dynamic-mechanical analysis and thermally stimulated depolarization currents, TSDC. Dielectric relaxation spectroscopy was used to characterize the relaxation behavior in the frequency domain. The strength of the alpha dielectric relaxation in poly(methyl methacrylate) network is small and the merging with the beta relaxation is not apparent in the experimental frequency range. On the contrary, in poly(butyl acrylate) networks it is the strength of the secondary relaxation which is small compared to that of the a relaxation and the relaxation spectrum has the characteristics of the latter in the whole experimental temperature interval. In the copolymer networks, the introduction of butyl acrylate segments in the polymer chains shifts the a process toward lower temperatures with respect to poly(methyl methacrylate) and increases the relaxation strength of the alpha relaxation. The crossover region is shown in copolymers with methyl methacrylate content ranging between 20 and 60 wt %. Nevertheless, in the IPNs with similar compositions the relaxation spectrum shows the characteristics of a secondary relaxation. This behavior is ascribed to the fact that the glass transition of the IPN is dispersed in an extremely broad temperature range, so its relaxation strength at each temperature is quite small, being not significant in comparison to that of the beta relaxation.	en
heal.publisher	AMER CHEMICAL SOC	en
heal.journalName	Macromolecules	en
dc.identifier.doi	10.1021/ma049429r	en
dc.identifier.isi	ISI:000223448300030	en
dc.identifier.volume	37	en
dc.identifier.issue	17	en
dc.identifier.spage	6472	en
dc.identifier.epage	6479	en