General Description : An amorphous, transparent and pale amber high performance thermoplastic with the characteristics common to this group - see PEEK. Like PEI,its properties are somewhat inferior to PEEK and it is less expensive. It has a slightly higher temperature resistance than PEI (but less than PEEK) and is the most temperature resistant transparent commercially available thermoplastic. It has a relatively high water absorption and, in common with many other plastics, drying is essential before e.g. thermoforming. It has poor fatigue characteristics and is prone to environmental stress cracking but has good long term thermal ageing resistance and reasonable radiation resistance. Its chemical resistance is not as wide as PEEK's; hence stable solutions can be made if solvents are correctly chosen.

Applications include electrical and electronic components, medical etc. equipment that needs repeated sterilisation and photographic accessories.