Comparative dielectric studies of segmental and normal mode dynamics of poly(oxybutylene) and poly(oxyethylene)-poly(oxybutylene) diblock copolymers

Kyritsis, A; Pissis, P; Mai, SM; Booth, C

dc.contributor.author	Kyritsis, A	en
dc.contributor.author	Pissis, P	en
dc.contributor.author	Mai, SM	en
dc.contributor.author	Booth, C	en
dc.date.accessioned	2014-03-01T01:15:30Z
dc.date.available	2014-03-01T01:15:30Z
dc.date.issued	2000	en
dc.identifier.issn	0024-9297	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/13553
dc.subject	Normal Modes	en
dc.subject.classification	Polymer Science	en
dc.subject.other	INVERTED CIS-POLYISOPRENE	en
dc.subject.other	BLOCK-COPOLYMERS	en
dc.subject.other	POLY(PROPYLENE GLYCOL)	en
dc.subject.other	RELAXATION BEHAVIOR	en
dc.subject.other	GLASS-TRANSITION	en
dc.subject.other	AQUEOUS-SOLUTION	en
dc.subject.other	BULK SYSTEMS	en
dc.subject.other	SPECTROSCOPY	en
dc.subject.other	MICELLIZATION	en
dc.subject.other	BLENDS	en
dc.title	Comparative dielectric studies of segmental and normal mode dynamics of poly(oxybutylene) and poly(oxyethylene)-poly(oxybutylene) diblock copolymers	en
heal.type	journalArticle	en
heal.identifier.primary	10.1021/ma990429e	en
heal.identifier.secondary	http://dx.doi.org/10.1021/ma990429e	en
heal.language	English	en
heal.publicationDate	2000	en
heal.abstract	Diblock copolymers of ethylene oxide and 1,2-butylene oxide, E30Bn, with constant E-block length of 30 units and various B-block lengths (n = 3-30) were investigated, in parallel with a series of homopoly(oxybutylene)s of similar to B-block lengths, using broad-band dielectric relaxation spectroscopy (10(-2)-10(9) Hz). The normal mode relaxation process due to reorientation of the end-to-end vector and the main (segmental) process caused by local chain motions, exhibited by the B-blocks in the copolymers and by the homopoly(oxybutylene), were studied in comparison to each other. The dynamics of the free chains in the liquid homopolymers is described more appropriately by the Rouse model, whereas the B-blocks in the crystallized copolymers exhibit significantly different dynamics. The results show that the B-blocks in the copolymers, constrained between lamellar crystals created by E-blocks, are more oriented and expanded, as compared to the chain conformation of the homopolymers. Comparative study of normal mode and main relaxations reveals, only for the homopolymers, a correlation length xi for the main process on the order of 1-2 nm at temperatures close to the glass transition temperature, T-g.	en
heal.publisher	AMER CHEMICAL SOC	en
heal.journalName	MACROMOLECULES	en
dc.identifier.doi	10.1021/ma990429e	en
dc.identifier.isi	ISI:000087655500046	en
dc.identifier.volume	33	en
dc.identifier.issue	12	en
dc.identifier.spage	4581	en
dc.identifier.epage	4595	en