A model for ranking thermoplastic and thermosetting compounds for HV applications

The author reports a preliminary model which allows the ranking of thermoplastic and thermosetting compounds for high-voltage applications using ASTM data on various properties. He considered only 18 of the most widely used thermoplastics and five thermosetting compounds. The dielectric and electrical properties included in the ranking are dielectric constant, dielectric loss factor, volume resistivity, and arc resistance. The mechanical and thermal properties considered are tensile strength and impact strength, deflection temperature, and maximum operating temperature. These and other properties are assigned a ranking between 1 and 5 corresponding to the material being poor if ranked 1 and very good if ranked 5. It is found that out of the materials evaluated, only a handful earned an index number in the satisfactory to good range. It is concluded that probably no solid insulating material is available which would be ranked excellent for all dielectric, electrical, mechanical, thermal, and other physical properties