Polyamide imide (PAI)

Used for aerospace applications, it is initially moulded as a thermoplastic and then postcured to produce partial thermosetting properties including improved temperature resistance. Hot/wet in service temperature ~ 190°C. These resins have a good resistance to UV, gamma radiation and wear and have low smoke emissions during combustion. However they are expensive and difficult to injection mould, in addition to this they absorb moisture and are susceptible to attack by alkalis, oxidising agents and formic acid.