Polyetherimide

Polyetherimide

Names
Other names PEI
Identifiers
CAS Number	61128-46-9 Y
ChemSpider	none
ECHA InfoCard	100.126.800
CompTox Dashboard (EPA)	DTXSID90976644
Properties
Chemical formula	(C37H24O6N2)n
Molar mass	Variable
Appearance	Amber-to-transparent solid
Density	1.27 g/cm3
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). N verify (what is YN ?) Infobox references

Polyetherimide (PEI) is an amorphous, amber-to-transparent thermoplastic with characteristics similar to the related plastic PEEK. Relative to PEEK, PEI is cheaper, but is lower in impact strength and usable temperature.

Due to its adhesive properties and chemical stability it became a popular bed material for FFF 3D printers.

Structure

The molecular formula of the repeating unit of PEI is C₃₇H₂₄O₆N₂ and the molecular weight is 592.61 g/mol.

Properties

The glass transition temperature of PEI is 217 °C (422 °F). Its amorphous density at 25 °C is 1.27 g/cm³(.046 lb/in³). It is prone to stress cracking in chlorinated solvents. Polyetherimide is able to resist high temperatures with stable electrical properties over a wide range of frequencies. This high strength material offers excellent chemical resistance and ductile properties suitable for various applications, even those including steam exposure.

Ultem

Ultem is a trademarked family of PEI products. It is a common brand name for polyetherimide.