Polystyrene (PS) is a thermoplastic designed for applications requiring excellent electrical and mechanical properties together with good processability. Polystyrenes have well-balanced physical properties and are generally transparent, but available in various colors.
Cross-linked polystyrene copolymer is a rigid, transparent, and colorless material with outstanding electrical properties, including low dielectric losses up to very high frequencies, and very high radiation resistance. Compared to normal polystyrene, it is harder and somewhat more temperature resistant. Cross-linked polystyrene has good dimensional stability, can be easily machined, and polishes to a high optical quality.
Rexolite® brand is a cross-linked polystyrene, microwave plastic. It’s most notable properties are unusually stable electrical properties into the giga-hertz frequency range. It is also optically clear (approximately the same as acrylic), dimensionally stable, and possesses excellent sound transmission characteristics. Grades include glass. Rexolite® may be ordered in sheet thicknesses to 1/4" with copper-clad surface in thicknesses ranging from 1/2-ounce to 2-ounce copper.