After two years of intensive research, BASF is now able to present prototypes of the world's first particle foam based on polyethersulfone (PESU). The foam is characterized by its unique combination of properties: high-temperature resistance, inherent flame retardancy - and its extreme light weight coupled with great stiffness and strength. It is therefore particularly well suited for complex-shaped components in cars, airplanes and trains, which require excellent mechanical properties together with the ability to withstand high operating temperatures or to meet stringent flame-retardant requirements. The expandable PESU granulate is pre-foamed into beads with low densities between 40 and 120 g/L and can be processed into molded parts with complex 3D geometries using technologies available on the market.
Ultrason® E, the PESU of BASF, is an amorphous thermoplastic with an extraordinary temperature profile: It has a high glass transition temperature of 225°C and remains dimensionally stable up to this temperature. Its excellent mechanical and dielectric properties are only slightly dependent on the temperature, too. Foams made of Ultrason® E are approved for use in aircraft. The material, with its exceptionally high limiting oxygen index of 38 (according to ASTM D 2863), distinguishes itself because it meets the requirements for commercial aircraft with regard to combustibility, low heat release and low smoke density ("fire, smoke, toxicity") even without the addition of flame retardants, which means it is intrinsically flame retardant.
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