of physical and chemical properties

Epoxy resin is a widely used material in medium and high voltage apparatus either for bulk or surface insulation. If the last steps of life of outdoor insulation are well known under humidity with the step of ageing is still not understood. To help in understanding ageing mechanisms, various compared to epoxy resin. The main parameters that are and the hydrolysis of the organic matrix. The performed tests are humidity cycles for 8 hours with an alternative voltage, the comparison of the materials is based on the 50 Hz currents, temperature and light emission for samples containing various water contents.