Silicone rubber（SiR） possesses outstanding electrical characteristics

and its dielectric properties are easily affected by molecular chain motion and electrode polarization. We employed infrared spectroscopy and X-ray photoelectron spectroscopy to analyze the functional group and element in SiR specimen. Then

the glass-transition temperature was measured as a value of-123 ℃ owing to different scanning calorimetry（DSC）. Frequency domain spectroscopy（FDS） was applied to detect the dielectric relaxation process in SiR at different temperatures. According to the FDS results the relaxation process α & δ caused by molecular chain motion could be observed on a high-frequency domain

while the DC conductivity induced by ion drift appeared on a low-frequency domain

particularly

an electrode polarization process appeared apparently on low frequency domain at high temperatures（140～200 ℃）. The relaxation process α& δ caused by molecular chain motion followed the Cole-Davidson relaxation function

based on which the dielectric relaxation intensity and relaxation time distribution at different temperatures were calculated. Besides

the relaxation time constant of relaxation process α & δ as a function of reciprocal temperature obeyed the Arrhenius equation

with an activation energy of 0.10 eV and 0.14 eV respectively. Then

according to the Macdonald model

the polarization electrode process in SiR was analyzed

and corresponding parameters such as the free ion density

Debye length

free ion mobility

and diffusivity at different temperatures were obtained. The temperature dependency of free ion mobility obeyed the Arrhenius equation

with an activation energy of 0.39 eV. At last

the thermal stimulated depolarization current（TSDC） was applied to confirm the existence of relaxation process α & δ and electrode polarization.