Deformation and Phase Behavior of Thermo-Mechanically Modified As-Spun Polyester Fibers
Valentin Velev1, Hristo Hristov2, Anton Popov3, Todor Dimov4
1Valentin L. Velev, Asst. Prof., Faculty of Natural Sciences, Konstantin Preslavsky University, Shumen, Bulgaria.
2Hristo Y. Hristov, Asst. Prof., Faculty of Natural Sciences, Konstantin Preslavsky University, Shumen, Bulgaria.
3Anton N. Popov, Asst. Prof., Central Scientific Research Laboratory, University “Prof. Dr. Assen Zlatarov” – Burgas, Burgas, Bulgaria.
4Todor N. Dimov, Asst. Prof., Faculty of Natural Sciences, Konstantin Preslavsky University, Shumen, Bulgaria.
Manuscript received on 23 March 2015 | Revised Manuscript received on 30 March 2015 | Manuscript published on 30 March 2015 | PP: 4-7 | Volume-4 Issue-1, March 2015 | Retrieval Number: A1331034115©BEIESP
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© The Authors. Blue Eyes Intelligence Engineering and Sciences Publication (BEIESP). This is an open access article under the CC-BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/)
Abstract: Thermo mechanically induced dimensional changes, birefringence and degree of crystallinity in amorphous poly (ethylene terephthalate) PET fibers were investigated. The heat mechanical treatments and optical measurements of the investigated filaments were performed by specialized devices constructed and made in the author’s laboratories. Undrawn PET yarns were subjected on heat mechanical modification at constant temperature of 950C above their glass transition temperature combined with tensile stress with values from 0MPa to 30MPa. Birefringence measurements and differential scanning calorimetry (DSC) were used in order to identify the occurred structural changes. Was established the effect of the superposition “annealing temperature/tensile stress” on the filaments birefringence as well as the dominant role of the strain stress on the fibers degree of crystallinity. It was found correlation between the filaments deformation behavior and the crystallization process in the studied PET objects.
Keywords: Birefringence, Deformation Behavior, Degree of Crystallinity, Fibers, Strain Stress
Scope of the Article: Mechanical Design