Polyethersulfone

Polyethersulfone (PESU) is a high-temperature thermoplastic polymer in the polyarylsulfone family. It consists of aromatic rings linked by ether (–O–) and sulfone (–SO2–) groups, resulting in a rigid, typically amorphous material with exceptional thermal and chemical stability.

Key properties of PESU include a high glass transition temperature in the range of about 180–220 °C, strong hydrolytic and chemical resistance, and good mechanical strength with excellent dimensional stability over a wide temperature range. It is generally transparent and exhibits good creep resistance. Compared with many other polymers, PESU maintains properties in the presence of acids, bases, and many organic solvents, and it is inherently flame resistant. These attributes make PESU suitable for demanding engineering applications.

Processing and forms: As a thermoplastic, PESU can be melted and processed by extrusion, injection molding, or solution casting. It is soluble in a variety of polar organic solvents such as N,N-dimethylformamide (DMF) and N,N-dimethylacetamide (DMAc), which enables film and membrane casting. Processing requires careful temperature control to preserve mechanical integrity and solvent compatibility. PESU parts and membranes are commonly fabricated in film, membrane, tubing, and molded component forms.

Applications: The most prominent use of PESU is in high-performance membranes for water treatment, pharmaceutical filtration, and sterile medical devices, including hemodialysis membranes. It is also employed in chemical processing components, high-temperature fluid handling, and other applications requiring chemical resistance and dimensional stability at elevated temperatures.

Synthesis: PESU is produced by condensation polymerization of difunctional aromatic monomers containing ether and sulfone linkages, yielding a polymer with repeating ether–sulfone–aryl units. It is related to other polyarylsulfones and is marketed in various grades by multiple manufacturers.