Interfacial effect of acetophenone on high field dielectric characteristics and electrical conduction of polyethylene

The interfacial effect of acetophenone on high-field dielectric characteristics and electrical conduction in low-density polyethylene (LDPE) has been investigated experimentally. The results show that the DC conduction current is significantly enhanced by the acetophenone coating. The permeation of acetophenone through the island structure of a gold-evaporated electrode onto the surface layer of LDPE modifies surface electronic states, apparently augmenting the injection of electronic carriers, especially holes. Tan δ of acetophenone-coated specimens increases in the high-temperature and high-field regions. Since tan δ in these regions normally decreases linearly with frequency, the dominance of DC conduction loss due to carrier motions is implied. The capacitance is also increased by the acetophenone coating. This can be attributed to the space charge polarization of injected carriers due to the coating, dipolar polarization of permeated acetophenone in polymer matrix, or both