Investigations on electric properties of polymers—II. Dielectric relaxation in atactic polystyrene determined by thermally stimulated depolarization currents

✍ Scribed by I. Diaconu; Sv. Dumitrescu

• Publisher: Elsevier Science
• Year: 1978
• Tongue: English
• Weight: 319 KB
• Volume: 14
• Category: Article
• ISSN: 0014-3057
• DOI: 10.1016/0014-3057(78)90098-8

✦ Synopsis

The thermally stimulated depolarization currents (TSDC) from atactic polystyrene and d.c. conductivity of the same material have been studied over the temperature ranges 20~395 K and 363-393 K respectively. TSDC spectra are complex and consist of four peaks, ill,/32, f13 (f13 of reduced intensity) and ~ in order of increasing temperature. The first three peaks appeared below the glass transition temperature Tg of the polymer. The /3j peak seems to arise from a single dipolar relaxation process. The/32 peak and probably f13 arise from a distribution in activation energy of dipolar relaxation processes, On the basis of the molecular origin of the /3 relaxation process, it was suggested that fit, [32 and /33 peaks involve motions of backbone chain fragments of various lengths. The last peak appeared at T 9 and could be considered as a result of dipole relaxation and electric conductivity. TSDC peaks and d.c. conductivity have been related to the second order transition in the polymer.