Molecular mobility of stannoxane modified epoxy resins

Kosma, S; Raftopoulos, K; Pissis, P; Strachota, A; Matejka, L; Ribot, F; Nedbal, J

dc.contributor.author	Kosma, S	en
dc.contributor.author	Raftopoulos, K	en
dc.contributor.author	Pissis, P	en
dc.contributor.author	Strachota, A	en
dc.contributor.author	Matejka, L	en
dc.contributor.author	Ribot, F	en
dc.contributor.author	Nedbal, J	en
dc.date.accessioned	2014-03-01T01:56:20Z
dc.date.available	2014-03-01T01:56:20Z
dc.date.issued	2007	en
dc.identifier.issn	17904439	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/28070
dc.relation.uri	http://www.scopus.com/inward/record.url?eid=2-s2.0-75149158871&partnerID=40&md5=755ed7fe2e56168e383f330f69a6a300	en
dc.subject	Glass transition	en
dc.subject	Polymer dynamics	en
dc.subject	Rubbery epoxy network	en
dc.subject	Stannoxane cluster	en
dc.subject.other	Broadband dielectric relaxation spectroscopy	en
dc.subject.other	Chain contours	en
dc.subject.other	Dielectric response	en
dc.subject.other	Dielectric techniques	en
dc.subject.other	Diglycidyl ether of bisphenol-A	en
dc.subject.other	Functionalized	en
dc.subject.other	Higher temperatures	en
dc.subject.other	Hybrid nanocomposites	en
dc.subject.other	Jeffamines	en
dc.subject.other	Modified epoxy	en
dc.subject.other	Molecular mobility	en
dc.subject.other	Normal modes	en
dc.subject.other	Poly(oxypropylene) diamine	en
dc.subject.other	Polymer dynamics	en
dc.subject.other	Rubbery epoxy network	en
dc.subject.other	Rubbery epoxy networks	en
dc.subject.other	Stannoxane cluster	en
dc.subject.other	Thermally stimulated depolarization currents	en
dc.subject.other	Transition shifts	en
dc.subject.other	Differential scanning calorimetry	en
dc.subject.other	Epoxy resins	en
dc.subject.other	Ethers	en
dc.subject.other	Glass	en
dc.subject.other	Nanocomposites	en
dc.subject.other	Phenols	en
dc.subject.other	Polymers	en
dc.subject.other	Resins	en
dc.subject.other	Spectroscopy	en
dc.subject.other	Glass transition	en
dc.title	Molecular mobility of stannoxane modified epoxy resins	en
heal.type	journalArticle	en
heal.publicationDate	2007	en
heal.abstract	Broadband dielectric relaxation spectroscopy (DRS) and, in addition, thermally stimulated depolarization currents (TSDC), a dielectric technique in the temperature domain, and differential scanning calorimetry (DSC) were employed to investigate polymer dynamics and glass transition in rubbery epoxy networks prepared from diglycidyl ether of bisphenol A (DGEBA) and poly(oxypropylene)diamine (Jeffamine® D2000, molar mass 2000) and their hybrid nanocomposites with the stannoxane ""Sn4"" cluster. In the nanocomposites a fraction x of Jeffamine chains (x=0.10, 0.25, 0.50) was replaced by diamino-functionalized stannoxanne clusters having the same functionality (4). Jeffamine D2000 and, for comparison, Jeffamine® D400 were also investigated. Four relaxations, the secondary γ and β relaxations, the a relaxation associated with the glass transition and the normal mode (NM) relaxation related with the presence of a dipole moment component along the chain contour, were identified and analyzed in the network and the hybrids, all having their origin in Jeffamine. Due to crosslinking the relaxations slow down in the pure network as compared to Jeffamine D2000, in particular the cooperative α and NM relaxations. The results by the three techniques suggest, in agreement with each other, that the structure becomes more rigid in the hybrids, as compared to the pure network: the glass transition shifts by a few degrees to higher temperatures and the α relaxation slows down. The local, secondary γ and β relaxations, on the contrary seem unaffected. The hybrid with the highest stannoxane content (x=0.50) exhibits a peculiar behaviour with an extremely broad glass transition and significantly reduced dielectric response.	en
heal.journalName	Journal of Nanostructured Polymers and Nanocomposites	en
dc.identifier.volume	3	en
dc.identifier.issue	4	en
dc.identifier.spage	144	en
dc.identifier.epage	156	en