TY - JOUR
T1 - Dielectric spectroscopic analysis of degradation in ethylene-propylene-diene copolymer
AU - Min, Daomin
AU - Li, Shengtao
AU - Hirai, Naoshi
AU - Ohki, Yoshimichi
N1 - Funding Information:
This research was partly supported by the Nuclear Regulation Authority, Japan, the National Basic Research Program of China (No. 2015CB251003), and Xi'an Jiaotong University (No. xjj2014022), China.
Publisher Copyright:
© 2016 IEEE.
PY - 2016/12
Y1 - 2016/12
N2 - Gamma-ray induced changes occurring in ethylene-propylene-diene copolymer (EPDM) were analyzed through its complex permittivity spectra. First, four different processes, namely, instantaneous polarization, hopping of ions, segmental relaxation, and dc conduction are found to contribute to the complex permittivity. By fitting the spectra to theoretical equations, it has become clear that the instantaneous polarization and ionic hopping become active by the irradiation, indicating that generation of oxidative products and mobile ions and occurrence of chain scission are induced by gamma rays. Furthermore, since both the thermal expansion and the contribution of the segmental relaxation to the permittivity become less with an increase in dose, it is assumed that crosslinking is induced by the gamma irradiation.
AB - Gamma-ray induced changes occurring in ethylene-propylene-diene copolymer (EPDM) were analyzed through its complex permittivity spectra. First, four different processes, namely, instantaneous polarization, hopping of ions, segmental relaxation, and dc conduction are found to contribute to the complex permittivity. By fitting the spectra to theoretical equations, it has become clear that the instantaneous polarization and ionic hopping become active by the irradiation, indicating that generation of oxidative products and mobile ions and occurrence of chain scission are induced by gamma rays. Furthermore, since both the thermal expansion and the contribution of the segmental relaxation to the permittivity become less with an increase in dose, it is assumed that crosslinking is induced by the gamma irradiation.
KW - Degradation
KW - EPDM
KW - dielectric property
KW - gamma irradiation
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U2 - 10.1109/TDEI.2016.005868
DO - 10.1109/TDEI.2016.005868
M3 - Article
AN - SCOPUS:85010369511
SN - 1070-9878
VL - 23
SP - 3620
EP - 3630
JO - IEEE Transactions on Dielectrics and Electrical Insulation
JF - IEEE Transactions on Dielectrics and Electrical Insulation
IS - 6
M1 - 7823416
ER -