Polysulfone (PSU) plastics comprise polysulfone [—Ph—C(CH3 )2 —Ph—O—Ph—SO2 —O—]n, polyester sulfone [—O—Ph—SO2 —O—]n and polyphenylsulfone [—O—Ph—SO2 —Ph— O—Ph—Ph—]n with the aryl radical Ph = C6 H4 . The isopropylidene linkage imparts chemical resistance, the ether bond imparts temperature resistance, while the sulfone linkage imparts impact strength. The brittleness temperature of polysulfones is –100°C. Polysulfones are clear, strong, nontoxic, and virtually unbreakable. However, stress cracking can be a problem and should be considered before use. PSU do not hydrolyze during autoclaving and they are resistant to acids, alkalis, aqueous solutions, aliphatic hydrocarbons, and alcohols. Hence they have added another dimension to thermoplastics in heat resistance and strength at high temperature. The ease of molding the material, and its retention of properties as temperatures increase, has made it one of the faster growing resins in the market place. Use of the product for chemical equipment applications has not been noted to date but is anticipated.
