| Title: |
Effect of recrystallization on the molecular mobility of a copolymer of vinylidene fluoride and hexafluoropropylene. |
| Authors: |
Valentin V. Kochervinskij; Inna A. Malyshkina; Natalia P. Bessonova; Sergey N. Suljanov; Kirill A. Dembo |
| Source: |
Journal of Applied Polymer Science; Apr2011, Vol. 120 Issue 1, p13-20, 8p |
| Subject Terms: |
COPOLYMERS; DIELECTRICS; FUSION (Phase transformation); RECRYSTALLIZATION (Metallurgy); RELAXATION phenomena |
| Abstract: |
Relaxation processes in copolymers of vinylidene fluoride with hexafluoropropylene (93/7) were studied by means of a dielectric method. The initial extruded film was recrystallized by free heating to temperatures above the melting point and by subsequent cooling. This increased both the perfection of the crystal phase and the degree of crystallinity. The impact of recrystallization on both the relaxation times (Ï's) and the activation parameters of the local mobility (β process) and microâBrownian cooperative mobility in amorphous phase (αaprocess) was almost negligible, whereas the Ï's of the αcrelaxation were an order of magnitude higher after recrystallization. Qualitatively, it was predicted by the soliton model for the αcrelaxation. The recrystallization affected characteristics of the transition at the highest temperature (α) registered in the region of the melting of the crystals even more. The process is related to the relaxation of the space charge formed by ionogenic impurities, which migrate through the amorphous phase with high free volume. It was shown that the dynamics in the amorphous phase controlled the drift mobility of free charge carriers and, by that, determined the Ï of the space charge relaxation process. The structuring processes during the recrystallization also affected the parameters of the orderâdisorder transition in the lowâperfect ferroelectric (antiferroelectric) phase. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011 [ABSTRACT FROM AUTHOR] |
| : |
Copyright of Journal of Applied Polymer Science is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.) |
| Database: |
Complementary Index |