Hot electron and partial-discharge induced ageing of polymers

Insulating polymers used in electrical engineering applications age under the combined effects of electrical, thermal, mechanical and environmental stresses. Of particular relevance is the electric stress that can initiate material degradation reactions through energetic processes such as partial discharges and hot electrons. Although the degradation can take specific form (microcavities, electrical treeing) depending on the time scale considered, similarities might exist in the aging mechanisms of polymers working in high voltage environment, and those exposed to plasma or radiation. Of particular interest is to identify the polymer excited states that are involved in the early stage of electrical ageing. Information on their nature can be obtained by analyzing the solid state luminescence stimulated by an electric field, UV source or fast electron beam. (C) 2003 Elsevier B.V. All rights reserved.