Dielectric and thermal properties of irradiated polyetheretherketone

Author

Shiyama, K. ; Fujita, S.

Author_Institution

Hachinohe Inst. of Technol., Japan

Volume

8

Issue

3

fYear

2001

fDate

6/1/2001 12:00:00 AM

Firstpage

538

Lastpage

542

Abstract

The dielectric and thermal properties of electron-beam-irradiated polyetheretherketone (PEEK) have been investigated and the properties of a heat-treated specimen studied. Results of the temperature dependence of ε_r\´ and ε_r" indicated that ε _r\´ and ε_r" were higher after electron beam irradiation and lower after heat treatment. The temperature at which ε_r\´ begins to increase and that at which the peak of ε_r" appears, rise with both electron beam irradiation and heat treatment. Glass transition temperature T_g values were calculated from graphs depicting the relationship between logarithmic values of τ(T_m) data and T_m, through the use of the Williams-Landel-Ferry (WLF) equation. T_g shifted to higher temperatures with either irradiation or heat treatment Results suggest that electron beam irradiation causes crosslinking among molecules via free radicals in the specimen. Consequently, crosslinking among molecules via free radicals is thought to occur with heat treatment

Keywords

dielectric relaxation; differential scanning calorimetry; electron beam effects; free radical reactions; glass transition; heat treatment; permittivity; plastics; polymers; radiation chemistry; DSC; PEEK; Williams-Landel-Ferry equation; crosslinking; dielectric properties; electron beam irradiation; free radicals; glass transition temperature; heat treatment; heat-treated specimen; permittivity; polyetheretherketone; temperature dependence; thermal properties; Dielectric loss measurement; Dielectric materials; Dielectric measurements; Dielectrics and electrical insulation; Electron beams; Glass; Heat treatment; Polymers; Resistance heating; Temperature;

fLanguage

English

Journal_Title

Dielectrics and Electrical Insulation, IEEE Transactions on

Publisher

ieee

ISSN

1070-9878

Type

jour

DOI

10.1109/94.933380

Filename

933380