Chemistry:Polyetherimide
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Names | |
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Other names
PEI, Ultem
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Identifiers | |
ChemSpider |
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Properties | |
(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). | |
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Infobox references | |
Polyetherimide (PEI; branded as Ultem[1]) is an amorphous, amber-to-transparent thermoplastic with characteristics similar to the related plastic PEEK. When comparing PEI to PEEK, the former is cheaper but has lower impact strength and a tighter temperature range.[2]
Due to its adhesive properties and chemical stability it became a popular bed material for FFF 3D printers.
Structure
The molecular formula of the PEI repeating unit is C
37H
24O
6N
2 and the molecular weight is 592.61 g/mol.[3] It contains phthalimide and bisphenol A sub-units.
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 while maintaining 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 involving steam exposure.[4]
References
- ↑ "Ultem". Curbell Plastics. https://www.curbellplastics.com/materials/plastics/ultem/.
- ↑ http://www.mcmaster.com/#ultem/=otzvqt Referenced Oct 7, 2013
- ↑ Scott, Chris. "polyetherimide information and properties" (in en). http://www.polymerprocessing.com/polymers/PEI.html.
- ↑ "Injection Molding Material Selection Guide" (in en-US). http://www.abtecinc.com/production/materials/.
![]() | Original source: https://en.wikipedia.org/wiki/Polyetherimide.
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