Viscoelastic properties of epoxy resins derived from creep and relaxation tests at different temperatures

Theocaris, PS

dc.contributor.author	Theocaris, PS	en
dc.date.accessioned	2014-03-01T01:37:39Z
dc.date.available	2014-03-01T01:37:39Z
dc.date.issued	1962	en
dc.identifier.issn	00354511	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/21590
dc.title	Viscoelastic properties of epoxy resins derived from creep and relaxation tests at different temperatures	en
heal.type	journalArticle	en
heal.identifier.primary	10.1007/BF01972534	en
heal.identifier.secondary	http://dx.doi.org/10.1007/BF01972534	en
heal.publicationDate	1962	en
heal.abstract	Experimental data have been obtained on the creep compliance and the relaxation modulus of two epoxy resins in their transition regions. These tests were combined with birefringence measurements to follow the changes in bond orientation of the polymers as the strain or stress varies. Experimental data on the stress- and strain-optical coefficients are presented for both creep and relaxation experiments. It was proved that the validity of the time-temperature superposition principle can be extended to these two coefficients characterizing the optical viscoelastic properties of the two epoxy resins. Master curves of F (t/k) versus log (t/k) were constructed, where F (t/k) represents in turn one of the quantities studied namely creep compliance, relaxation modulus and stress- or strain-optical coefficients. The creep and relaxation time factors k, corresponding to the creep and relaxation curves at the various temperatures, are plotted against the inverse of the absolute temperature T. The approximate equality of the time factors for mechanical and separately for optical creep and relaxation was established from these plots. This equality proves that creep D-functions and relaxation E-functions are the reciprocals of one another at any time and that the variation of birefringence with time follows the same law in the respective creep and relaxation tests. © 1962 Dr. Dietrich Steinkopff-Verlag.	en
heal.publisher	Steinkopff-Verlag	en
heal.journalName	Rheologica Acta	en
dc.identifier.doi	10.1007/BF01972534	en
dc.identifier.volume	2	en
dc.identifier.issue	2	en
dc.identifier.spage	92	en
dc.identifier.epage	96	en