No. 1383
	Evaluation of Properties and Improvement of Polymeric Insulating Materials for Outdoor Use
	Investigating R&D Committee on Evaluation of Properties and Improvement of Polymeric Insulating Materials for Outdoor Use
	Keyword : Polymeric insulator, silicone rubber, hydrophobicity, outdoor insulation, aging
	Since polymeric insulators show superior performance in workability, earthquake resistance, and electrical insulation under pollution conditions than porcelain insulators. Therefore, uses of polymeric insulators have rapidly expanded in recent years. Since polymeric insulators are mainly constructed with organic materials, it is necessary to overcome some technical problems related to the degradation due to aging. The investigation committee surveyed some kind of properties of polymeric insulating materials for outdoor use such as silicone rubber. The cutting edge of material development and evaluation methods on these materials were focused on. To clarify the material properties, extensive investigation was also executed based on experimental data using the common specimens designed by the committee. Relation between the specific properties of materials and requirement for the insulator products was discussed. The major investigation items are classified as follows. * Quantitative evaluation of hydrophobicity of polymeric insulating materials * Discharge phenomena and aging of polymeric insulating materials * Relation between surface properties and discharge phenomena under natural conditions * Test methods to evaluate material performance * Improvement of surface properties of polymeric insulating materials These investigation provided lots of advanced knowledge about hydrophobicity of silicone rubbers, discharge phenomena, and aging properties due to the discharge. There are still remaining subjects, e.g. evaluation on hydrophobicity, clarification of the relation between surface conditions and discharge phenomena.
	©2007. The Institute of Electrical Engineers of Japan