These are a class of heat-resistant and fairly strong synthetic fibers of orange to yellow color.

They are prepared by a two-step process from aromatic diamines and dianhydrides. Polyimides perform in demanding applications where very high temperature, corrosion, wear, and creep resistance is required. Polyimides fibers are produced by a dry-spinning process from a polyamic acid solution. The precursor fibers are then transferred into polyimide fibers by a subsequent heat treatment process.  Unlike polyester and acrylic fibers, polyimides have a much higher glass transition temperature (about 400°C) and a much higher melting point. Due to their aromatic structure, polyimide fibers have very low flammability and excellent chemical resistance  Continue reading here

Current applications:

• Hot gas filtration bags
• Protective clothing
• Separation membranes

Why should I choose polyimide fibres?

• High Tg
• Flame retardancy

Considerations:

• Dianhydrides must be matched to the corresponding diamines for optimal properties of the polyimide.

Additional reading:

• “P84® Polyimide Fibres Properties, technical data and product range,” Evonik