PI - Polyimide
Polyimide (abbreviated PI) resins are different from many other of the high performance resins in that they are thermoset as opposed to thermoplastic. (Although there are versions of thermoplastic Polyimides) There are a variety of companies that manufacture polyimide films and structural shapes.
Polyimides are known for thermal stability, good chemical resistance, excellent mechanical properties, and characteristic orange/yellow color. They exhibit very low creep and high tensile strength . Polyimides retain their properties over an extremely wide thermal range, and can withstand excursions up to 900 °F (482 °C). Polyimides are also inherently resistant to flame combustion. Typical polyimide parts are not affected by commonly used solvents and oils — including hydrocarbons, esters, ethers, and alcohols. They also resist weak acids but are not recommended for use in environments that contain alkalis or inorganic acids.
Benefits & Liabilities of PI
- Benefits:
- Excellent High temperature mechanical performance
- Very high tensile and compressive strength
- Excellent wear poroperties
- High purity
- Good chemical resistance
- Unaffected by radiation
Liabilities:
- Very high cost
- Requires high processing temperatures
- Attacked by concentrated acids and alkalis
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