Study of Iodine-Doped Poly(Ethyl Methacrylate)Relaxation by Thermally Stimulated Depolarization Currents and Thermal Sampling Method

摘要

Corona poling and thermally stimulated depolarization current(TSDC)techniques have been used to study the relaxation behaviour of pure and iodine-doped poly(ethyl methacrylate)(PEMA)in the vicinity of the glass transition temperature(T_g).Different parameters such as,corona field and corona temperature,have been used.The global TSDC spectrum of pure PEMA with varying poling field and poling temperature revealed that pure PEMA is characterized by only a single relaxation peak located at T=349 K.On the other hand,iodine-doped PEMA samples are characterized by two distinguished relaxation peaks.The first one has been observed in the temperature range from 347 K to 363 K,whereas,the second one has been detected at a higher temperature side at T~ 395 K.Based on the results,the origin of the TSDC peak was attributed to a superposition of dipolar relaxation and space-charge which build up.Thermal sampling(TS)technique was used to get more information about the fine structure of pure and iodine-doped PEMA samples.