Abstract :
A digest is given of known factors contributing to the usefulness of highpolymeric resins for electrical applications. General properties such as good mechanical and heat stability, oxidation, radiation resistance, chain regularity leading to partial crystallinity, as well as absence of reactive groups and aliphatic hydrogen are discussed. The electrical requirements are so many that it is difficult to perceive a common denominator. Absence of polar groups, for instance, is generally required for low dielectric constant, but on the other hand groups of good electron affinity are needed as traps for displaced electrons. Based on such considerations, the good and weak points of most customary dielectrics are examined, and the paper further analyzes the anticipated or known properties of new materials appearing on the market, the use of which can be expected in the not-to-distant future. In doing this, an attempt is made to correlate molecular structure with performance, and thus help designers to understand their needs in terms of chemical properties, or to assist in the tailormaking of special-purpose materials.