PSU or polysulfones are rigid, high-strength and transparent. They are also characterized by high strength and stiffness, retaining these properties between -100 °C and 150 °C. The glass transition temperature of polysulfones is between 190 to 230 °C. They have a high dimensional stability, the size change when exposed to boiling water or 150 °C air or steam generally falls below 0.1%.
Polysulfone is highly resistant to mineral acids, alkali, and electrolytes, in pH ranging from 2 to 13. It is resistant to oxidizing agents, therefore it can be cleaned by bleaches. It is also resistant to surfactants and hydrocarbon oils. It is not resistant to low-polar organic solvents (e.g. ketones and chlorinated hydrocarbons) and aromatic hydrocarbons. Mechanically, polysulfone has high compaction resistance, recommending its use under high pressures. It is also stable in aqueous acids and bases and many non-polar solvents; however, it is soluble in dichloromethane and methylpyrrolidone. Polysulfone is not used in wear applications.