Molecular Mobility and Hydration Properties of Segmented Polyurethanes with Varying Structure of Soft- and Hard-Chain Segments

Kanapitsas, A; Pissis, P; Gomez Ribelles, JL; Monleon Pradas, M; Privalko, EG; Privalko, VP

dc.contributor.author	Kanapitsas, A	en
dc.contributor.author	Pissis, P	en
dc.contributor.author	Gomez Ribelles, JL	en
dc.contributor.author	Monleon Pradas, M	en
dc.contributor.author	Privalko, EG	en
dc.contributor.author	Privalko, VP	en
dc.date.accessioned	2014-03-01T01:14:50Z
dc.date.available	2014-03-01T01:14:50Z
dc.date.issued	1999	en
dc.identifier.issn	0021-8995	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/13239
dc.subject	Dielectric relaxation	en
dc.subject	Glass transition	en
dc.subject	Hydration properties	en
dc.subject	Incomplete microphase separation	en
dc.subject	Segmented polyurethanes	en
dc.subject.classification	Polymer Science	en
dc.subject.other	Dielectric relaxation	en
dc.subject.other	Differential scanning calorimetry	en
dc.subject.other	Hydration	en
dc.subject.other	Isotherms	en
dc.subject.other	Molecular dynamics	en
dc.subject.other	Molecular structure	en
dc.subject.other	Phase separation	en
dc.subject.other	Saturation (materials composition)	en
dc.subject.other	Sorption	en
dc.subject.other	Water	en
dc.subject.other	Equilibrium water-sorption isotherms	en
dc.subject.other	Molecular mobility	en
dc.subject.other	Thermally stimulated depolarization currents (TSDC)	en
dc.subject.other	Polyurethanes	en
dc.title	Molecular Mobility and Hydration Properties of Segmented Polyurethanes with Varying Structure of Soft- and Hard-Chain Segments	en
heal.type	journalArticle	en
heal.identifier.primary	10.1002/(SICI)1097-4628(19990222)71:8<1209::AID-APP1>3.0.CO;2-5	en
heal.identifier.secondary	http://dx.doi.org/10.1002/(SICI)1097-4628(19990222)71:8<1209::AID-APP1>3.0.CO;2-5	en
heal.language	English	en
heal.publicationDate	1999	en
heal.abstract	The molecular mobility and hydration properties of model segmented polyurethanes from either poly(propylene glycol) (PPG) or poly(butylene adipate) (PBAD), both of molecular weight 2000 (soft segments), and three different diisocyanates (all-trans 4,4'-dicyclohexylmethane diisocyanate, 100% t,t HMDI; HMDI with 20% of trans isomers, 20% t,t HMDI; and 4,4'-diphenylmethane diisocyanate, MDI) (hard segments) were investigated using differential scanning calorimetry (DSC), thermally stimulated depolarization currents (TSDC) measurements, ac dielectric relaxation spectroscopy (ac DRS), equilibrium water-sorption isotherms (ESI), and dynamic water-sorption isotherms (DSI). No effects of the structure and of the amount of the soft segments on the overall degree of microphase separation (DMS) into microphases rich in soft and hard segments, respectively, were observed. On the contrary, DMS depends on the composition of the diisocyanates used and systematically increases in the order MDI, 20% t,t HMDI, 100% t,t HMDI as indicated by DSC, TSDC, and ac DRS. The PPG-based polyurethanes are characterized by larger values of water content at saturation, h, and smaller values of the diffusion coefficient of water, D. h increases with temperature, indicating that the sorption process is endothermic. (C) 1999 John Wiley & Sons, Inc.	en
heal.publisher	JOHN WILEY & SONS INC	en
heal.journalName	Journal of Applied Polymer Science	en
dc.identifier.doi	10.1002/(SICI)1097-4628(19990222)71:8<1209::AID-APP1>3.0.CO;2-5	en
dc.identifier.isi	ISI:000077785700001	en
dc.identifier.volume	71	en
dc.identifier.issue	8	en
dc.identifier.spage	1209	en
dc.identifier.epage	1221	en