Polyoxymethylene

Polyoxymethylene
Names
	Other names Poly(oxymethylene) glycol; polymethylene glycol
Identifiers
CAS Number	9002-81-7 ;
ChemSpider	None;
UNII	QHG55SH7ER ;
CompTox Dashboard (EPA)	DTXSID001010896 ;
Properties
Chemical formula	(CH2O)n
Molar mass	Variable
Appearance	White solid (undyed)
Density	1.41–1.42 g/cm3
Melting point	165 °C (329 °F)
Electrical resistivity	14×1015 Ω⋅cm
Magnetic susceptibility (χ)	−9.36×10−6 (SI, at 22 °C)
Thermochemistry
Heat capacity (C)	1500 J/kg·K
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). verify (what is ?) Infobox references

Polyoxymethylene (POM), also known as acetal,^[4] polyacetal, and polyformaldehyde, is an engineering thermoplastic used in precision parts requiring high stiffness, low friction, and excellent dimensional stability. Short-chained POM (chain length between 8 and 100 repeating units) is also better known as paraformaldehyde (PFA). As with many other synthetic polymers, polyoxymethylenes are produced by different chemical firms with slightly different formulas and sold variously by such names as Delrin, Kocetal, Ultraform, Celcon, Ramtal, Duracon, Kepital, Polypenco, Tenac and Hostaform.

POM is characterized by its high strength, hardness and rigidity to −40 °C. POM is intrinsically opaque white because of its high crystalline composition but can be produced in a variety of colors.^[1] POM has a density of 1.410–1.420 g/cm³.^[5]

Typical applications for injection-molded POM include high-performance engineering components such as small gear wheels, eyeglass frames, ball bearings, ski bindings, fasteners, gun parts, knife handles, and lock systems. The material is widely used in the automotive and consumer electronics industry. POM's electrical resistivity is 14×10¹⁵ Ω⋅cm making it a dielectric with a 19.5MV/m breakdown voltage.^[2]^[6]

^ ^a ^b "Colored Delrin". Retrieved 12 March 2021.
^ ^a ^b ^c ^d "Data Sheet: POM (Delrin, Acetal)" (PDF). xometry.eu. 2021. Retrieved June 19, 2022.
^ Wapler, M. C.; Leupold, J.; Dragonu, I.; von Elverfeldt, D.; Zaitsev, M.; Wallrabe, U. (2014). "Magnetic properties of materials for MR engineering, micro-MR and beyond". JMR. 242: 233–242. arXiv:1403.4760. Bibcode:2014JMagR.242..233W. doi:10.1016/j.jmr.2014.02.005. PMID 24705364. S2CID 11545416.
^ "MatWeb:acetal".
^ "Ticona MSDS for Hostaform". Archived from the original on 2011-05-12.
^ Acetal (Polyoxymethylene)

[mw-1] "Colored Delrin". Retrieved 12 March 2021.

[xometry-2021-2] "Data Sheet: POM (Delrin, Acetal)" (PDF). xometry.eu. 2021. Retrieved June 19, 2022.

[3] Wapler, M. C.; Leupold, J.; Dragonu, I.; von Elverfeldt, D.; Zaitsev, M.; Wallrabe, U. (2014). "Magnetic properties of materials for MR engineering, micro-MR and beyond". JMR. 242: 233–242. arXiv:1403.4760. Bibcode:2014JMagR.242..233W. doi:10.1016/j.jmr.2014.02.005. PMID 24705364. S2CID 11545416.

[4] "MatWeb:acetal".

[5] "Ticona MSDS for Hostaform". Archived from the original on 2011-05-12.

[6] Acetal (Polyoxymethylene)

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