Polyimide(PI)

Polyimide (PI) — DuPont Vespel® Series

Polyimide (PI) is one of the highest-performing organic engineering polymers — rated for continuous use from −269°C to +300°C with no melting point. The DuPont Vespel® brand is the industry gold standard for extreme-environment PI components in aerospace, semiconductor, and defense applications.

Vespel® Grade Overview

  • SP-1 (yellow-brown): Unfilled — highest mechanical strength and electrical insulation
  • SP-21 (black): 15% graphite — excellent wear and heat resistance
  • SP-211 (black): 15% graphite + 10% PTFE — lowest static friction coefficient
  • SP-22 (black): 40% graphite — minimum thermal expansion, maximum creep resistance
  • SP-3 (black): 15% molybdenum disulfide — for vacuum and inert gas friction applications

Key Properties

  • Service temperature: −269°C to +300°C (short-term: +400°C)
  • Zero melting point — does not melt, only degrades at extreme temperatures
  • Radiation resistant — nuclear, X-ray, gamma
  • Excellent dimensional stability and creep resistance
  • Outstanding machinability for precision components

Applications

Aerospace thrust washers and bushings · Semiconductor process chamber parts · Vacuum equipment seals and insulators · Rocket engine components · Cryogenic instruments