PEI

Polyetherimide is an amorphous thermoplastic polymer with a very high
Tg. It has a high strength and Young's Modulus and a low creep, also at high
temperatures. It has a low coefficient of thermal expansion, which
results in a very good dimensional stability.
PEI is chemically stabile at high temperatures for long periods and is
inherently flame retardant with low smoke emission, which makes it
suitable for application in aircraft interiors.
It has a good chemical resistance against many chemicals and acids,
but it is less resistant to bases.
Good resistance to most sterilisation methods, so very suitable for
medical applications.

Specific properties
Density: 1.27-1.32 g/cm3, glass filled grades higher.

Mechanical properties: High strength and Young's Modulus (3.3 GPa),
higher than most other amorphous polymers. Reasonable ductility.

Thermal properties: Tg 217 °C, HDT 205 °C. Inherently flame retardant,
low smoke and toxic gas emissions.

Chemical resistance: Very good for an amorphous polymer: good
resistance against acids and many organic liquids such as oils and
greases, cooling liquids, alcohols and (halogenated) hydrocarbons.
Not resistant to strong bases, above pH 9.

Colour/surface
In the natural unfilled state transparent yellow, such as the material
coin. Colouring possible but difficult due to the very high processing
temperature. Can be metallised using various methods for use in MID’s
and reflectors.

Processing
Injection mouldable at temperatures between 340 °C and 395 °C.
Can be extruded. Material must be dried before processing.

Applications
Aerospace: matrix for thermoplastic fiber composites, air and
fuel valves, interior components
Automotive industry: transmission components, sensor and
thermostat housings.
Medical: (reusable) medical devices, sterilisation trays, dentist
devices, pipettes.
Industrial: water-pump impellers, valves, hot water reservoirs,
heat exchange systems.
Electronics: moulded interconnect devices (MID’s), computer
and mobile phone components.
Catering: microwavable bowls, steam pans, food trays.