Title :
Anomalous discharge process in copolymers of vinylidene fluoride
Author :
Murata, Yukinobu ; Koizumi, Naokazu
Author_Institution :
Osaka Prefectural Tech. Coll., Neyagawa, Japan
Abstract :
Anomalous discharge behavior involving the occurrence of a current peak in the isothermal discharge process has been observed for vinylidene fluoride-trifluoroethylene (VDF/TFE) copolymers in the paraelectric phase. The current peak was found for VDF/TFE copolymer with high TFE content in the paraelectric and also for VDF/HFP (hexafluoropropylene) copolymer with 2 mol.% HFP taking structure of the form 11 PVDF (polyvinylidene fluoride). The anomalous behavior is connected with retarded migration or diffusion of ionic charge bound with molecular dipoles in crystalline regions. The VDF group or the VDF sequence in the copolymer possibly plays an important role in trapping or restraining ions
Keywords :
dielectric properties of solids; electrets; electric breakdown of solids; ionic conduction in solids; polymer blends; TFE; VDF; copolymers; crystalline regions; electrets; ion trapping; ionic charge diffusion; isothermal discharge process; molecular dipoles; paraelectric phase; retarded migration; vinylidene fluoride-trifluoroethylene; Conductivity; Crystallization; Current measurement; Dielectric measurements; Dielectrics and electrical insulation; Ferroelectric materials; Isothermal processes; Plastic insulation; Polymers; Temperature dependence;
Conference_Titel :
Electrets, 1991. (ISE 7) Proceedings., 7th International Symposium on (Cat. No.91CH3029-6)
Conference_Location :
Berlin
Print_ISBN :
0-7803-0112-9
DOI :
10.1109/ISE.1991.167195
