Polyamideimides

Polyamide-imides (PAIs) are a class of high-performance polymers that incorporate both amide and imide linkages in their main chain. They are typically based on aromatic structures and are designed to withstand demanding operating conditions.

PAIs offer exceptional thermal stability, with high glass transition or melting temperatures and the ability to retain mechanical strength at elevated temperatures. They exhibit high modulus, excellent creep resistance, and good wear and abrasion resistance. They also show strong resistance to many solvents and fuels and have good flame resistance with low smoke generation in many grades. Their combination of properties makes them attractive for demanding environments.

Synthesis and processing of PAIs typically involve polycondensation of aromatic diamines with dianhydrides or diisocyanate/anhydride systems to form polyamide-imide backbones. Many commercial PAIs are supplied as amic acid precursors that imidize by heat to form the final polymer. They are thermoplastics that can be melt-processed or processed from solution, but require very high processing temperatures and equipment; they remain relatively insoluble in common solvents.

Applications include electrical insulation (connectors, lead frames, coil forms), aerospace and automotive components (gears, valves, wear parts), coatings, and binders for high-temperature applications, as well as specialty mechanical parts exposed to harsh environments. Accessory formulations may tailor toughness, abrasion resistance, or chemical resistance for specific end uses.