Filled epoxy compositions hardened with the pet chemical degradation product
* Ewa Fabrycy, Tadeusz Spychaj, Ryszard Pilawka, ** Janusz Michalski * Politechnika Szczecińska, Instytut Polimerów, ul. Pułaskiego 10, 70-322 Szczecin ** Politechnika Szczecińska, Instytut Elektrotechniki, ul. Sikorskiego 37, 70-313 Szczecin
Annals 2 No. 4, 2002 pages 149-152
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abstract Epoxy compositions and resulting composites based on Araldit F and Epidian 6 resins (Table 1) and inorganic fillers (silica, aluminum hydroxide and mixture of talc and kaolin (1:1 wt./wt.)) hardened with poly(ethylene terephthalate)/ triethanoloamine (PET/TEA) chemical degradation product have been prepared and characterized. Mineral fillers have been applied in amounts of 50 or 65 g per 100 g of epoxy resin. Two ratios of the PET/TEA hardener have been applied 16.5 or 19.2 g per 100 g of epoxy resin (equivalent to 7 or 6 epoxy groups of the resin per 1 nitrogen atom of the hardener, respectively). It has been found that life times of the filled epoxy compositions based on Epidian 6 resin (at 80°C) are similar to these of unfilled system with exception of that containing talk + kaolin mixture. In the last case life time is substantially prelonged (from 45 to 80 min). Mechanical properties (tensile, flexural and impact strengths) of the filled epoxy composites are decreased as compared with unfilled (Tables 2-4) whereas glass temperatures are almost unchanged (Tables 2 and 3). The composites show good electrical properties (dielectric constant, dielectric loss coefficient tgδ, volume resistivity, electric arc resistance and break down resistance) (Table 5) which are partially deteriorated after long time tests at elevated temperature (40°C) and humidity (95%) (Table 6). The lowest changes of electrical properties have been found for epoxy composites filled with silica and talc + kaolin mixture. The composites are considered as insulating materials for on-air insulators of low and medium voltage.