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Technical University of Crete
Technical University of Crete
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| URI | http://purl.tuc.gr/dl/dias/64576DAC-DCFA-4C28-8E1F-452EE631426A | - |
| Identifier | http://link.springer.com/article/10.1007/BF01357954 | - |
| Identifier | https://doi.org/10.1007/BF01357954 | - |
| Language | en | - |
| Extent | 12 pages | en |
| Title | Primary normal-stress difference for two liquid crystalline copolyesters | en |
| Creator | Gotsis Alexandros | en |
| Creator | Γκοτσης Αλεξανδρος | el |
| Creator | Baird, David, 1956- | en |
| Publisher | Springer Verlag | en |
| Content Summary | The primary normal-stress difference,N 1, was determined in both steady and transient shear flow experiments for thermotropic copolyesters of 60 and 80 mole% p-hydroxybenzoic acid (PHB) and polyethylene terephthalate (PET).N 1 was observed to be negative for the 80 mole% system at low shear rates and temperatures below 332 °C (a tensile stress, e.g. σ11 is taken here to be positive). At higher shear rates and for temperatures above 332 °C,N 1 was found to be positive. Values ofN 1 for the 60 mole% pHBA/PET system were always positive over the same range of shear rates. Although it is not certain as to the origin of the negative values, a probable cause is small density changes upon the inception of flow as well as the existence of a solid phase or some texture development in the melt. However, it is shown that it is thermodynamically admissible for liquid crystalline fluids to exhibit negative values ofN 1. | en |
| Type of Item | Peer-Reviewed Journal Publication | en |
| Type of Item | Δημοσίευση σε Περιοδικό με Κριτές | el |
| License | http://creativecommons.org/licenses/by/4.0/ | en |
| Date of Item | 2015-11-14 | - |
| Date of Publication | 1986 | - |
| Subject | Liquid crystalline copolyester | en |
| Subject | Shear flow | en |
| Subject | Negative primary normal-stress difference | en |
| Bibliographic Citation | A. D. Gotsis and D. G. Baird, "Primary normal-stress difference for two liquid crystalline copolyesters", Rheolog. Acta, vol. 25, no. 3, pp. 275-286, May 1986. doi:10.1007/BF01357954 | en |
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