Some new operational modes and parameters of stress relaxation for the viscoelastic characterization of solid polymers. III. The area ratio mode and the intrinsic "strain-clock" function

Kytopoulos, VN; Bourkas, GD; Sideridis, E

dc.contributor.author	Kytopoulos, VN	en
dc.contributor.author	Bourkas, GD	en
dc.contributor.author	Sideridis, E	en
dc.date.accessioned	2014-03-01T01:19:33Z
dc.date.available	2014-03-01T01:19:33Z
dc.date.issued	2003	en
dc.identifier.issn	0021-8995	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/15566
dc.subject	poly(propylene) (PP)	en
dc.subject	relaxation	en
dc.subject	modeling	en
dc.subject	viscoelastic properties	en
dc.subject	modulus	en
dc.subject.classification	Polymer Science	en
dc.title	Some new operational modes and parameters of stress relaxation for the viscoelastic characterization of solid polymers. III. The area ratio mode and the intrinsic "strain-clock" function	en
heal.type	journalArticle	en
heal.identifier.primary	10.1002/app.11168	en
heal.identifier.secondary	http://dx.doi.org/10.1002/app.11168	en
heal.language	English	en
heal.publicationDate	2003	en
heal.abstract	The introduced area ratio mode of operation with its corresponding parameters seems to have a fairly high sensitivity to the viscoelastic response of the solid polymer. This appeared from the fact that a good distinction among the linear viscoelastic, the nonlinear viscoelastic, and the viscoplastic ranges of behavior can be made. By using a relevant rheological modeling and its corresponding algorithmical approach, in the case of isotactic polypropylene, this material can be characterized as a morphological three-phase material consisting of an intraspherulitic crystalline, an amorphous phase, and a interspherulitic para-crystalline phase. In this sense, the material was simulated using two models: the Poynting-Thomson and the Maxwell-Wierchert, from where a good response of the material to the first model appeared. The so-called intrinsic "strain- clock" function and its corresponding coefficient of strength of nonlinear viscoelastic behavior, which were relieved by the experimental data, seem to be some powerful and very practical "tools" that can give a proven suplementary characterization of the material. Finally, by this intrinsic function, the existence of permanent internal stresses, was confirmed, in an indirect way, which was mentioned in part II of this study. (C) 2002 Wiley Periodicals, Inc.	en
heal.publisher	JOHN WILEY & SONS INC	en
heal.journalName	JOURNAL OF APPLIED POLYMER SCIENCE	en
dc.identifier.doi	10.1002/app.11168	en
dc.identifier.isi	ISI:000179267600005	en
dc.identifier.volume	87	en
dc.identifier.issue	2	en
dc.identifier.spage	149	en
dc.identifier.epage	158	en