Dielectric Materials - Synthetic Dielectrics

A number of traditional dielectric materials are still widely used in industry. For example, paper impregnated with oil is often still the insulator of choice for coating wires that carry high-voltage current. But synthetic materials have now become widely popular for many applications once filled by natural substances, such as glass and rubber. The advantage of synthetic materials is that they can be designed so as to produce very specific properties for specialized uses. These properties include not only low dielectric constant, but also strength, hardness, resistance to chemical attack, and other desirable qualities.

Among the polymers now used as dielectrics are the polyethylenes, polypropylenes, polystyrenes, polyvinyl chlorides, polyamides (Nylon), polymethyl methacrylates, and polycarbonates.