A ductile-brittle zone in polyimides depending on the reaction temperature

Theocaris, PS; Startsev, VM; Chugunova, NF

dc.contributor.author	Theocaris, PS	en
dc.contributor.author	Startsev, VM	en
dc.contributor.author	Chugunova, NF	en
dc.date.accessioned	2014-03-01T01:38:37Z
dc.date.available	2014-03-01T01:38:37Z
dc.date.issued	1984	en
dc.identifier.issn	0303402X	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/22293
dc.subject	caustics	en
dc.subject	ductile fracture	en
dc.subject	KI-factor	en
dc.subject	Polyimides	en
dc.subject	polymers	en
dc.subject.other	CHEMICAL REACTIONS - Thermal Effects	en
dc.subject.other	ELASTICITY - Theory	en
dc.subject.other	MATHEMATICAL TECHNIQUES	en
dc.subject.other	OPTICAL PROPERTIES	en
dc.subject.other	OPTICAL VARIABLES MEASUREMENT	en
dc.subject.other	DUCTILE-BRITTLE ZONES	en
dc.subject.other	REACTION TEMPERATURE	en
dc.subject.other	POLYIMIDES	en
dc.title	A ductile-brittle zone in polyimides depending on the reaction temperature	en
heal.type	journalArticle	en
heal.identifier.primary	10.1007/BF01452217	en
heal.identifier.secondary	http://dx.doi.org/10.1007/BF01452217	en
heal.publicationDate	1984	en
heal.abstract	The mechanical and optical properties of polyimides were studied in this paper and the influence of the variation of the reaction temperature on the physico-chemical properties of the polymers was evaluated. From this the dependence of the stress-strain diagrams on the reaction temperature, as well as the stresses and strains at fracture were experimentally determined. Moreover, the elastic moduli and Poisson's ratios, as well as the refractive index of the polymers were evaluated for different temperatures of imidization. In order to define also the behaviour of the polymers as thin membranes at fracture, simple tension tests with edge-cracked thin strips were executed up to fracture. The method of caustics was used, with the specimens loaded in KI mode of deformation at different stress-levels to evaluate the stress intensity factors of the materials in the non-linear zone of loading. The KI-factor was evaluated by applying the simple Dugdale-Barenblatt model for the ductile materials, whereas for brittle samples the elastic theory was used. Interesting results concerning the physico-mechanical properties of the polyimides were derived. © 1984 Steinkopff.	en
heal.publisher	Steinkopff-Verlag	en
heal.journalName	Colloid & Polymer Science	en
dc.identifier.doi	10.1007/BF01452217	en
dc.identifier.volume	262	en
dc.identifier.issue	11	en
dc.identifier.spage	867	en
dc.identifier.epage	875	en