Polyetherimide

Polyetherimide

Names
Other names PEI
Identifiers
CAS Registry Number	61128-46-9 Y
ChemSpider	N
Properties
Chemical formula	(C37H24O6N2)n
Molar mass	Variable
Appearance	Amber-to-transparent solid
Density	1.27 g/cm3
Except where noted otherwise, data is given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
N verify (what is: Y/N?)
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.^[1]

Structure

The molecular formula of the repeating unit of PEI is C₃₇H₂₄O₆N₂ and the molecular weight is 592 g/mol.

Properties

The glass transition temperature of PEI is 216 °C. Its amorphous density at 25 °C is 1.27 g/cm³. It is prone to stress cracking in chlorinated solvents.

Ultem

Ultem is a family of PEI products manufactured by SABIC as a result of acquiring the General Electric Plastics Division in 2007. Ultem resins are used in medical and chemical instrumentation due to their heat resistance, solvent resistance and flame resistance. Ultem 1000 (standard, unfilled polyetherimide) has a high dielectric strength, natural flame resistance, and extremely low smoke generation. Ultem has high mechanical properties and performs in continuous use to 340 °F (170 °C). Ultem 1000 has typical thermal conductivity of 0.22 W/(m·K) (but some sources give 0.122 W/(m.K)).

References