Influence of the structure of soft and stiff chain fragments on properties of segmented polyurethanes. I. Phase morphology

Privalko, VP; Privalko, EG; Shtompel, VI; Pissis, P; Kanapitsas, A; Pradas, MM; Ribelles, J-LG

dc.contributor.author	Privalko, VP	en
dc.contributor.author	Privalko, EG	en
dc.contributor.author	Shtompel, VI	en
dc.contributor.author	Pissis, P	en
dc.contributor.author	Kanapitsas, A	en
dc.contributor.author	Pradas, MM	en
dc.contributor.author	Ribelles, J-LG	en
dc.date.accessioned	2014-03-01T01:14:43Z
dc.date.available	2014-03-01T01:14:43Z
dc.date.issued	1999	en
dc.identifier.issn	0032-3888	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/13201
dc.subject.classification	Engineering, Chemical	en
dc.subject.classification	Polymer Science	en
dc.subject.other	Conformations	en
dc.subject.other	Crystal lattices	en
dc.subject.other	Glass transition	en
dc.subject.other	Glycols	en
dc.subject.other	Isomers	en
dc.subject.other	Molecular structure	en
dc.subject.other	Morphology	en
dc.subject.other	Oligomers	en
dc.subject.other	Phase separation	en
dc.subject.other	Solubility	en
dc.subject.other	Specific heat of solids	en
dc.subject.other	X ray scattering	en
dc.subject.other	Segmented polyurethanes	en
dc.subject.other	Polyurethanes	en
dc.title	Influence of the structure of soft and stiff chain fragments on properties of segmented polyurethanes. I. Phase morphology	en
heal.type	journalArticle	en
heal.identifier.primary	10.1002/pen.11546	en
heal.identifier.secondary	http://dx.doi.org/10.1002/pen.11546	en
heal.language	English	en
heal.publicationDate	1999	en
heal.abstract	Model segmented polyurethanes (SPUs) prepared from either oxypropylene glycol oligomer or butylene adipate glycol oligomer, both of molar mass 2 kg/mol (soft fragments, SFT), and three different diisocyanates (all-trans 4.4'-dicyclohexylmethane diisocyanate, t, t-HMDI-1.0; HMDI with 20% of trans isomers, t, t-HMDI-0.2; and 4, 4'-diphenylmethane diisocyanate, MDI) (stiff fragments, STF) were characterized by specific heat capacity measurements in the temperature interval 140-540 K, and by wide-angle and small-angle X-ray scattering at room temperature. Limited miscibility of SFT and STF chain components resulted in incomplete separation into a regular three-dimensional macrolattice of STF-rich microdomains and SFT-rich microphases. The composition of STF-rich microdomains was estimated by fitting the softening temperatures to the Couchman's equation, whereas the relative contents of SFT-rich and STF-rich microphases were assessed by comparing the specific heat capacity change at the glass transition temperatures to corresponding additive values. The overall degree of microphase separation, as well as the mean macrolattice spacings between STF microdomains decreased in the order, MDI > t, t-HMDI-1.0 much greater than t, t-HMDI-0.2. The conformation of STF fragments within the STF-rich microdomains changed h-om nearly extended (for MDI) through slightly contracted (for t, t-HMDI-1.0) to strongly contracted (for t, t-HMDI-0.2).	en
heal.publisher	Soc Plast Eng, Brookfield, CT, United States	en
heal.journalName	Polymer Engineering and Science	en
dc.identifier.doi	10.1002/pen.11546	en
dc.identifier.isi	ISI:000082319600025	en
dc.identifier.volume	39	en
dc.identifier.issue	8	en
dc.identifier.spage	1534	en
dc.identifier.epage	1540	en