| Polyetherimide | |
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Other names
PEI |
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| Identifiers | |
| CAS number | 61128-46-9 |
| Properties | |
| Molecular formula | (C37H24O6N2)n |
| Molar mass | Variable |
| Appearance | Amber-to-transparent solid |
| Density | 1.27 g/cm3 |
| (verify) (what is: /?) Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) |
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| 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 less temperature-resistant and lower in impact strength.
Contents |
The molecular formula of the repeating unit of PEI is C37H24O6N2 and the molecular weight is 592 g/mol.
The glass transition temperature of PEI is 216 °C. Its amorphous density at 25 °C is 1.27 g/cc. It is prone to stress cracking in chlorinated solvents.
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 is also used in guitar picks, most notably by the Dunlop Manufacturing (Ultex series) and InTune (Ultem-X series) companies.