BASF’s Ultrason E 2020 P SR micro has a higher share of hydroxyl end groups, making this version of the polyethersulfone (PESU) highly compatible with high-performance epoxy resins. It has already been used as an impact modifier in some composite applications.

In micro-powder form the heat resistant impact modifier is incorporated in the resin system more easily, according to BASF. Ultrason E 2020 P SR does not have to be solubilised in a solvent which subsequently has to be removed, saving customers time and money.
 
Heat resistant impact modifiers are used in sophisticated composites based on high-temperature resistant epoxy resins in airplanes and racing cars.