Yet another of the high strength, high temperature resistant polymers; with toughness and outstanding long term creep resistance being two of the more important characteristics of this amorphous material. PESU has the ability to maintain much of its strength at elevated temperatures. And, like Polyether-Imide, can be repeatedly steam sterilized without significantly affecting physical properties. PESU has good hydrolysis and chemical resistance. It is unaffected by non-oxidizing acids, bases, aqueous solutions, aliphatic hydrocarbons and alcohols. Concentrated oxidizing acids, ketones, esters, some aldehydes, some halogenated hydrocarbons and some aromatic hydrocarbons attack PESU while polar aromatic hydrocarbons are solvents for it. As well, PESU has good flame resistance and emits low amounts of smoke when burning. The resistance of PESU to deterioration by alpha, beta and gamma radiation is reasonable but UV degrades this material and only pigmenting with carbon black results in stability. The FDA has approved this product for direct food contact. With high temperature resistance and retention of electrical insulation properties over a wide range of temperature and frequency, PESU can be used in some "Class H" electrical applications. PSEU can be either solvent cemented or adhesive bonded using polar adhesives. In addition, it can be ultrasonic, butt, fusion and hot gas welded plus vacuum formed. Of particular interest is the ability of PESU to be plated and vacuum metalized without the need of a base lacquer. The machinability of PESU is very good using high-speed tooling at high speeds and high feed rates. To be safe water based emulsion coolants should be used to ensure that parts are not subject to chemical stress when machining. GLASS-FILLED grades should be machined using carbide.