1. Relationship between global and segmental dynamics of poly(butylene oxide) studied by broadband dielectric spectroscopy
- Author
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Minoru Yamane, Shota Tomie, Tadashi Inoue, Toshiyuki Shikata, Osamu Urakawa, and Keiichiro Adachi
- Subjects
chemistry.chemical_classification ,Range (particle radiation) ,Materials science ,Two step ,Dynamics (mechanics) ,Relaxation (NMR) ,Oxide ,General Physics and Astronomy ,Thermodynamics ,02 engineering and technology ,Polymer ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,chemistry.chemical_compound ,chemistry ,Normal mode ,Physical and Theoretical Chemistry ,0210 nano-technology ,Broadband dielectric spectroscopy - Abstract
Relationship between segmental relaxation and normal-mode relaxation has been studied for molten poly(butylene oxide)s having various molecular weights by broadband dielectric spectroscopy over a wide temperature (T) range. We found that T dependence of the segmental relaxation time, τs, was weaker than the normal mode time, τn, at high T(>250 K ∼ Tg + 50 K), and the τn/τs ratio systematically decreased with increasing temperature. This high temperature complexity, whose mechanism has not been discussed in detail so far, was quantitatively explained by assuming the two step processes: local conformation change of polymers (elementary process) occurs first, and then the motion of a segment unit (second process) occurs. It was also found that the elementary process was strongly correlated with the experimentally observed β-relaxation.
- Published
- 2018