Polyoxymethylene (acetal), POM POM
CH2O (smallest repeat unit as listed by NASA)
Polyoxymethylene (POM), also called acetal and sold as Delrin, is a semicrystalline engineering thermoplastic sold as a homopolymer or a copolymer.
Evidence level
5 of 5
Flown or field-proven
- 0Predicted only. No one has made it, or no measurement exists.
- 1Calculated. Only calculated or predicted values from sources.
- 2Lab-measured. Measured properties with their conditions stated.
- 3Space-relevant tests. Measured in conditions relevant to space, such as vacuum or atomic oxygen.
- 4Ground-qualified. Qualified for an application on the ground.
- 5Flown or field-proven. Flight or field results exist.
Stiff moulding grade
2700 MPa tensile modulus
Heat under load
101 °C HDT at 1.80 MPa
Survive in orbit
9.14e-24 cm3/atom
Recipe, share of the weight
- C 40.0%Carbon
- H 6.7%Hydrogen
- O 53.3%Oxygen
Best for
Stiff, dimensionally stable moulded parts: a 2700 MPa tensile modulus and 64 MPa yield stress in the C 13021 FC copolymer grade
Weakest at
Atomic oxygen in low Earth orbit: an erosion yield of 9.14e-24 cm3/atom on MISSE 2
Risk at a glance
- People Low. Formaldehyde hazard
- If it fails Severe. Chlorine attack
- Corrosion Severe. Chlorine attacks acetal at 3 to 5 ppm and higher, so long-term continuous exposure is not recommended.
Quick facts: POM
| Property | Value | Basis |
|---|---|---|
| Density | 1.41 to 1.42 g/cm³ | 3 sourced values across conditions |
| Thermal expansion (CTE) | 100 ppm/K | 1 sourced value |
| Melting point | 165 to 178 °C | 3 sourced values across conditions |
What is the density of Polyoxymethylene (acetal), POM?
Polyoxymethylene (acetal), POM has a density of 1.41 to 1.42 g/cm³. The range covers 3 sourced values across the tempers, forms and test conditions the sources report; room-temperature values are used where a source states a temperature.
What is the coefficient of thermal expansion of Polyoxymethylene (acetal), POM?
Polyoxymethylene (acetal), POM has a coefficient of thermal expansion of 100 ppm/K. The source and test conditions are listed in the properties table on this page.
What is the melting point of Polyoxymethylene (acetal), POM?
Polyoxymethylene (acetal), POM has a melting point of 165 to 178 °C. The range covers 3 sourced values across the tempers, forms and test conditions the sources report; room-temperature values are used where a source states a temperature.
What is Polyoxymethylene (acetal), POM used for?
Uses recorded in the sources include Gears and drive trains; Zippers and thin-section parts; Fasteners and snap-fits.
Why it exists
Polyoxymethylene is a semicrystalline engineering thermoplastic. The two Hostaform copolymer grades read here have a density of 1410 kg/m3 and melting temperatures of 165 °C (C 2521) and 166 °C (C 13021 FC) at 10 °C/min. Their tensile moduli are 2600 MPa and 2700 MPa.
Where it's used
Gears and drive trains
DuPont lists DELRIN 100 for gears and DELRIN 500CL for gears, drive trains and sliding devices.
Zippers and thin-section parts
DuPont lists DELRIN 900P, a low-viscosity grade for thin sections, for consumer electronics parts and zippers.
Fasteners and snap-fits
DuPont lists DELRIN 500 for snap-fits, fasteners and gears, and DELRIN 100T for fasteners and seat belt systems.
Recipe
CH2O (smallest repeat unit as listed by NASA)
Polyoxymethylene is a chain of repeating CH2O units, made from formaldehyde. The homopolymer is end-capped to stabilise it; the copolymer contains about 1 to 1.5 percent CH2CH2O units along the chain (Wikipedia, composition only; key wiki-pom).
| Ingredient | Atoms per unit | Share of the weight | What it does |
|---|---|---|---|
| Carbon C | 1 | 40.0% | One carbon per CH2O repeat unit, part of the backbone. |
| Hydrogen H | 2 | 6.7% | Two hydrogens per CH2O repeat unit. |
| Oxygen O | 1 | 53.3% | One ether oxygen per CH2O repeat unit, joining the backbone. |
Weight shares are calculated from standard atomic weights.
What it can do
Stiff moulding grade
2700 MPa tensile modulus
measured
Hostaform C 13021 FC has a tensile modulus of 2700 MPa and a yield stress of 64 MPa under ISO 527, as printed on its datasheet page.
Heat under load
101 °C HDT at 1.80 MPa
measured
Hostaform C 2521 has a temperature of deflection under load of 101 °C at 1.80 MPa, ISO 75-1/-2, as printed on its datasheet page.
Survive in orbit
9.14e-24 cm3/atom
measured
NASA lists a MISSE 2 erosion yield for polyoxymethylene of 9.14e-24 cm3/atom, in Table I.
How it compares
The two grades are read from one database, so compare the rows as examples for these two Hostaform grades, not as a ranking of all POM.
The same measurements for each material, so you can compare them. Each row names the key condition under the value; the full conditions and methods are in the numbered notes under Technical details. Compare every grade in the family.
| Measurement | POM |
|---|---|
| Thermal behavior and safety | |
| Melting temperature, Hostaform C 2521 (copolymer) | 165 °C2 |
| Temperature of deflection under load (HDT), Hostaform C 2521ISO 75-1/-2, as printed on the datasheet | 101 °C |
| Melting temperature, Hostaform C 13021 FC (copolymer) | 166 °C5 |
| Melting temperature, Delrin 500P NC010 (homopolymer)ISO 11357-3, as printed on the datasheet | 178 °C |
| Heat deflection temperature at 1.8 MPa (unannealed), Delrin 500P NC010ISO 75-2/A, as printed on the datasheet | 95 °C |
| Physical and electrical | |
| Density, Hostaform C 2521 (copolymer) | 1410 kg/m31 |
| Density, Hostaform C 13021 FC (copolymer) | 1410 kg/m34 |
| Density, Delrin 500P NC010 (homopolymer)ISO 1183, as printed on the DuPont datasheet | 1.42 g/cm³ |
| Temperature behavior | |
| Vicat softening temperature, Delrin 500P NC010ISO 306/B50, as printed on the datasheet | 155 °C |
| Other measurements | |
| Tensile modulus, Hostaform C 2521 (copolymer)ISO 527, as printed on the datasheet | 2600 MPa |
| Yield stress, Hostaform C 2521 (copolymer)ISO 527, as printed on the datasheet | 62 MPa |
| Nominal strain at break, Hostaform C 2521 (copolymer)ISO 527, as printed on the datasheet | 32 % |
| Charpy notched impact strength at +23 °C, Hostaform C 2521ISO 179/1eA, as printed on the datasheet | 8.5 kJ/m23 |
| Tensile modulus, Hostaform C 13021 FC (copolymer)ISO 527, as printed on the datasheet | 2700 MPa |
| Yield stress, Hostaform C 13021 FC (copolymer)ISO 527, as printed on the datasheet | 64 MPa |
| Nominal strain at break, Hostaform C 13021 FC (copolymer)ISO 527, as printed on the datasheet | 30 % |
| Charpy notched impact strength at +23 °C, Hostaform C 13021 FCISO 179/1eA, as printed on the datasheet | 6 kJ/m26 |
| Atomic oxygen erosion yield, POM (MISSE 2) | 9.14×10^-24 cm³/atom7 |
| Tensile modulus, Delrin 500P NC010 (homopolymer)ISO 527-2, as printed on the datasheet | 3100 MPa |
| Tensile stress at yield, Delrin 500P NC010 (homopolymer)ISO 527-2, as printed on the datasheet | 71 MPa |
| Nominal tensile strain at break, Delrin 500P NC010 (homopolymer)ISO 527-2, as printed on the datasheet | 30 % |
| Flexural modulus, Delrin 500P NC010 (homopolymer)ISO 178, as printed on the datasheet | 3000 MPa |
| Charpy notched impact strength at 23 °C, Delrin 500P NC010 (homopolymer)ISO 179/1eA, as printed on the datasheet | 9 kJ/m28 |
| Coefficient of linear thermal expansion, flow direction, Delrin 500P NC010 | 1×10^-4 cm/cm/°C9 |
Why choose it, and why not
Good for
- Stiff moulded parts: 2700 MPa tensile modulus and 64 MPa yield stress in Hostaform C 13021 FC, as printed.
- Known atomic oxygen behaviour: 9.14e-24 cm3/atom on MISSE 2 in low Earth orbit.
Watch out for
- Atomic oxygen erodes POM at 9.14e-24 cm3/atom, so exterior use needs protection or a rate allowance.
- No Delrin homopolymer value was read, so the numbers here are for copolymer grades only.
- Flexural modulus and Izod impact were not found on the datasheets read.
Polyoxymethylene is a stiff engineering plastic: the two copolymer grades read have a density of 1410 kg/m3, a melting temperature of 165 to 166 °C, and a tensile modulus of 2600 to 2700 MPa. Its MISSE 2 erosion yield of 9.14e-24 cm3/atom is recorded, and no homopolymer Delrin data is in this profile yet.
Technical details
For scientists and researchers. Everything above comes from the record below: every number with its method, its conditions and its source.
Notes
The method, full conditions and any caveat for the numbered rows above.
| # | Measurement | Method | Conditions | Caveat |
|---|---|---|---|---|
| 1 | Density, Hostaform C 2521 (copolymer) | ISO 1183, as printed on the Material Data Center datasheet | grade Hostaform C 2521, POM copolymertemperature not printed on the page | — |
| 2 | Melting temperature, Hostaform C 2521 (copolymer) | ISO 11357-1/-3 (DSC), as printed on the datasheet | grade Hostaform C 2521, POM copolymerrate 10 °C/min | — |
| 3 | Charpy notched impact strength at +23 °C, Hostaform C 2521 | — | grade Hostaform C 2521, POM copolymertemperature +23 °Cnotch type A, as printed | — |
| 4 | Density, Hostaform C 13021 FC (copolymer) | ISO 1183, as printed on the Material Data Center datasheet | grade Hostaform C 13021 FC, POM copolymertemperature not printed on the page | — |
| 5 | Melting temperature, Hostaform C 13021 FC (copolymer) | ISO 11357-1/-3 (DSC), as printed on the datasheet | grade Hostaform C 13021 FC, POM copolymerrate 10 °C/min | — |
| 6 | Charpy notched impact strength at +23 °C, Hostaform C 13021 FC | — | grade Hostaform C 13021 FC, POM copolymertemperature +23 °Cnotch type A, as printed | — |
| 7 | Atomic oxygen erosion yield, POM (MISSE 2) | Measured on MISSE 2 flight samples and listed in NASA TM-2008-215490 | platform ISS, MISSE 2 PEC 2 tray 1, low Earth orbitfluence 8.43e21 atoms/cm2duration 3.95 years | — |
| 8 | Charpy notched impact strength at 23 °C, Delrin 500P NC010 (homopolymer) | — | grade Delrin 500P NC010, POM homopolymertemperature 23 °C (73 °F)notch type A, ISO 179/1eA | — |
| 9 | Coefficient of linear thermal expansion, flow direction, Delrin 500P NC010 | ISO 11359-2, as printed on the datasheet (printed as 1.0E-4 cm/cm/°C) | grade Delrin 500P NC010, POM homopolymerdirection flow | — |
Corrosion and compatibility
What happens when it meets other materials and environments.
| Environment | Concern | What happens |
|---|---|---|
| Chlorine gas and bleaching fluid | severe | Chlorine attacks acetal at 3 to 5 ppm and higher, so long-term continuous exposure is not recommended.1 |
| Zinc chloride, and salt water in contact with zinc-plated steel | moderate | Zinc chloride depolymerises acetal; salt water alone does not affect it.2 |
| Strong acids and strong bases; steam and hot water | moderate | Service life is reduced by lengthy use in steam, hot water, strong acids or strong bases.3 |
| Hot water and strong caustic or high pH solutions, copolymer against homopolymer | low | Copolymer acetal resists hot water and strong caustics better than homopolymer, per Alro.4 |
| Sunlight UV (290 to 400 nm), outdoors and through glass | moderate | Acetal is affected by sunlight; UV-stabilised grades are offered for outdoor and glass-behind use.5 |
| Gamma radiation | moderate | DuPont gives depolymerisation as the predominant degradation mode under gamma ray dosage.6 |
| Unstressed exposure in air at 60 C, long term | low | DELRIN 500 keeps a tensile strength above 55 MPa for about 5 years at 60 C.7 |
| Fuels: M-15 gasoline (15 percent methanol) and diesel at 60 C | low | Standard grades change only slightly after 1500 h in M-15 and hardly at all in diesel.8 |
| # | Environment | Details | Test conditions |
|---|---|---|---|
| 1 | Chlorine gas and bleaching fluid | DuPont states that DELRIN acetal resin is attacked by chlorine at concentrations of 3 to 5 ppm and higher, and is not recommended for long term continuous exposure at these concentrations. Its rating table marks chlorine gas and 10 percent bleaching fluid as unsatisfactory. | basis unstressed specimens in continuous exposure; rating table at ambient temperature |
| 2 | Zinc chloride, and salt water in contact with zinc-plated steel | DuPont says zinc chloride acts to depolymerise (corrode) DELRIN acetal resin, with attack depending on stress, temperature, concentration and time. Salt water alone does not affect it, but salt water with zinc-plated steel can give a slower effect similar to zinc chloride. | basis stress, temperature, concentration and time are not quantified in the guide |
| 3 | Strong acids and strong bases; steam and hot water | DuPont lists steam, hot water, strong acids and strong bases as reducing service life. Its rating table marks hydrochloric acid (10 percent), sulphuric acid (30 percent), nitric acid (10 percent), perchloric acid (10 percent) and phosphoric acid (30 percent) as unsatisfactory, and acetic acid (5 percent) as resistant. | basis unstressed specimens at ambient temperature; the guide says intermittent exposure and service stresses can change the result |
| 4 | Hot water and strong caustic or high pH solutions, copolymer against homopolymer | Alro lists better resistance to hot water and strong caustics, or high pH solutions, as an advantage of acetal copolymer over homopolymer. No temperature, concentration or time is printed. | basis comparison of copolymer and homopolymer, no test figures printed |
| 5 | Sunlight UV (290 to 400 nm), outdoors and through glass | DuPont says acetal resins, like most polymers, are affected by light, particularly sunlight with ultraviolet radiation of 290 to 400 nm. It lists UV-stabilised grades (for example DELRIN 127UV, 527UV and 927UV) with excellent UV resistance and thermal stability, and says the x27UV series suits parts exposed to sunlight through glass. No retention figure is printed. | wavelength 290 to 400 nmbasis grade dependent; no dose or retention figure printed |
| 6 | Gamma radiation | DuPont says that the predominant mode of degradation resulting from gamma ray dosage is depolymerisation. The guide prints no dose figure in the text read. | dose not printed in the text read |
| 7 | Unstressed exposure in air at 60 C, long term | DuPont's long-term exposure curve for unstressed injection-moulded bars in air says DELRIN 500 would keep a tensile strength in excess of 55 MPa for approximately 5 years at 60 C. | temperature 60 Cstress none, unstressedgrade DELRIN 500 |
| 8 | Fuels: M-15 gasoline (15 percent methanol) and diesel at 60 C | DuPont aged DELRIN 500 and 500P NC010 for up to 1500 hours at 60 C in M-15, and reports only small changes from slight plastification by fuel absorption. In diesel, bio-diesel and kerosene it reports almost no change in dimensional or mechanical properties after 2000 hours at 60 C. | temperature 60 Ctime up to 1500 h in M-15; up to 2000 h in dieselfuel M-15 is regular gasoline with 15 percent methanol |
Risks and side effects
Hazards to people, what happens when a cell overheats, and how the material is handled and stored.
For people
POM has no GHS entry in PubChem; the hazard here is formaldehyde, the monomer it is made from.
- Classification
- Formaldehyde carries H302, H314, H317, H330, H341 and H350 (PubChem aggregated). Chlorine and strong acids are a corrosion risk for parts, not a listed hazard for people.
If it fails
The failure route in these sources is erosion in orbit, measured on one flight sample.
- Atomic oxygen
- On MISSE 2 the erosion yield was 9.14e-24 cm3/atom, from the same NASA report.
Test details
The original wording and numbers from the sources, for readers who want them.
Failure risks
| Failure | Trigger and consequence |
|---|---|
| Atomic oxygen erosion in low Earth orbitmoderate severity | Exposure of a POM part to atomic oxygen in low Earth orbit, as on the MISSE 2 flightSurface erosion at a yield of 9.14e-24 cm3/atom as measured on MISSE 2 |
| Chlorine attackcritical severity | Chlorine gas or bleach at 3 to 5 ppm and higher, in long-term continuous exposureAttack on the acetal; DuPont rates chlorine gas and 10 percent bleaching fluid as unsatisfactory |
| Zinc chloride depolymerisationmoderate severity | Zinc chloride, or salt water in contact with zinc-plated steelDepolymerisation (corrosion) of the acetal, depending on stress, temperature, concentration and time |
| Strong acid or strong base attackmoderate severity | Lengthy use in strong acids or strong bases, or in steam and hot waterShorter service life; DuPont rates hydrochloric, sulphuric, nitric and phosphoric acids at 10 to 30 percent as unsatisfactory |
| UV degradation in sunlightmoderate severity | Sunlight UV at 290 to 400 nm on standard grades, outdoors or through glassLight-induced degradation; UV-stabilised grades are offered for this exposure |
| Gamma radiation depolymerisationmoderate severity | Gamma ray dosageDuPont gives depolymerisation as the predominant degradation mode |
Handling and storage
- Keep chlorine, bleach and chlorinated water away from stressed parts. DuPont does not recommend long-term continuous exposure at 3 to 5 ppm chlorine and above.
- Use local extraction where heating or processing may release formaldehyde; the formaldehyde GHS codes above are the reason. No POM-specific release figure was read.
Mitigations
- For sunlight exposure, choose a UV-stabilised grade such as DELRIN 127UV, 527UV or 927UV, per the DuPont grade list.
- For hot water or strong caustic service, choose a copolymer grade, which Alro says resists these better than homopolymer.
Supply and geography
How common the raw materials are and where they come from.
Formaldehyde, the feedstock for POM
POM resin, made by polymerisation of formaldehyde
- Top producers
- Polyplastics (Daicel), Celanese, DuPont
Documents
Datasheets, safety data sheets, papers and standards you can open.
Full record
The complete spore, as stored. Free to reuse under CC-BY-4.0. Images keep the licence shown with each one.
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spore: profile
id: pom-delrin
spore_version: 0.2
family: engineering-polymers
name: Polyoxymethylene (acetal), POM
abbreviation: POM
role: engineering thermoplastic for precision moulded parts; Delrin is a DuPont trade name for POM
category: polymers
type: acetals
summary: |
Polyoxymethylene (POM), also called acetal and sold as Delrin, is a semicrystalline engineering thermoplastic sold as a homopolymer or a copolymer. Two Celanese Hostaform copolymer grades read for this profile have a density of 1410 kg/m3 (ISO 1183), a melting temperature of 165 °C (C 2521) and 166 °C (C 13021 FC) at 10 °C/min, and a tensile modulus of 2600 MPa (C 2521) and 2700 MPa (C 13021 FC). As a sample on the MISSE 2 experiment in low Earth orbit it had an atomic oxygen erosion yield of 9.14e-24 cm3/atom (NASA TM-2008-215490, Table I). No homopolymer Delrin datasheet was read in this run.
best_for: 'Stiff, dimensionally stable moulded parts: a 2700 MPa tensile modulus and 64 MPa yield stress in the C 13021 FC copolymer grade'
weakest_at: 'Atomic oxygen in low Earth orbit: an erosion yield of 9.14e-24 cm3/atom on MISSE 2'
identity:
name: Polyoxymethylene (acetal), POM (Delrin)
formula: CH2O (smallest repeat unit as listed by NASA)
source: nasa-tm-2008-215490
where: Table IV, column Formula
tags:
environments:
- low-earth-orbit
stresses:
- atomic-oxygen
- vacuum-and-outgassing
applications: []
properties:
- benchmark: density
label: Density, Hostaform C 2521 (copolymer)
value: 1410
unit: kg/m3
scope: material
conditions:
grade: Hostaform C 2521, POM copolymer
temperature: not printed on the page
method: ISO 1183, as printed on the Material Data Center datasheet
status: ground
source: mdc-hostaform-c2521
where: Datasheet table, row Density (Other properties)
- benchmark: melting_point
label: Melting temperature, Hostaform C 2521 (copolymer)
value: 165
unit: °C
scope: material
conditions:
grade: Hostaform C 2521, POM copolymer
rate: 10 °C/min
method: ISO 11357-1/-3 (DSC), as printed on the datasheet
status: ground
source: mdc-hostaform-c2521
where: Datasheet table, row Melting temperature, 10°C/min
- benchmark: tensile_modulus
label: Tensile modulus, Hostaform C 2521 (copolymer)
value: 2600
unit: MPa
scope: material
conditions:
grade: Hostaform C 2521, POM copolymer
test: ISO 527 as printed
method: ISO 527, as printed on the datasheet
status: ground
source: mdc-hostaform-c2521
where: Datasheet table, row Tensile Modulus
- benchmark: tensile_yield_strength
label: Yield stress, Hostaform C 2521 (copolymer)
value: 62
unit: MPa
scope: material
conditions:
grade: Hostaform C 2521, POM copolymer
test: ISO 527 as printed
method: ISO 527, as printed on the datasheet
status: ground
source: mdc-hostaform-c2521
where: Datasheet table, row Yield stress
- benchmark: nominal_strain_at_break
label: Nominal strain at break, Hostaform C 2521 (copolymer)
value: 32
unit: '%'
scope: material
conditions:
grade: Hostaform C 2521, POM copolymer
test: ISO 527 as printed
method: ISO 527, as printed on the datasheet
status: ground
source: mdc-hostaform-c2521
where: Datasheet table, row Nominal strain at break
- benchmark: charpy_notched_impact
label: Charpy notched impact strength at +23 °C, Hostaform C 2521
value: 8.5
unit: kJ/m2
scope: material
conditions:
grade: Hostaform C 2521, POM copolymer
temperature: +23 °C
notch: type A, as printed
method: ISO 179/1eA, as printed on the datasheet
status: ground
source: mdc-hostaform-c2521
where: Datasheet table, row Charpy notched impact strength, +23°C
- benchmark: heat_deflection_temperature
label: Temperature of deflection under load (HDT), Hostaform C 2521
value: 101
unit: °C
scope: material
conditions:
grade: Hostaform C 2521, POM copolymer
load: 1.80 MPa
method: ISO 75-1/-2, as printed on the datasheet
status: ground
source: mdc-hostaform-c2521
where: Datasheet table, row Temp. of deflection under load, 1.80 MPa (HDT)
- benchmark: density
label: Density, Hostaform C 13021 FC (copolymer)
value: 1410
unit: kg/m3
scope: material
conditions:
grade: Hostaform C 13021 FC, POM copolymer
temperature: not printed on the page
method: ISO 1183, as printed on the Material Data Center datasheet
status: ground
source: mdc-hostaform-c13021fc
where: Datasheet table, row Density (密度)
- benchmark: melting_point
label: Melting temperature, Hostaform C 13021 FC (copolymer)
value: 166
unit: °C
scope: material
conditions:
grade: Hostaform C 13021 FC, POM copolymer
rate: 10 °C/min
method: ISO 11357-1/-3 (DSC), as printed on the datasheet
status: ground
source: mdc-hostaform-c13021fc
where: Datasheet table, row Melting temperature, 10°C/min
- benchmark: tensile_modulus
label: Tensile modulus, Hostaform C 13021 FC (copolymer)
value: 2700
unit: MPa
scope: material
conditions:
grade: Hostaform C 13021 FC, POM copolymer
test: ISO 527 as printed
method: ISO 527, as printed on the datasheet
status: ground
source: mdc-hostaform-c13021fc
where: Datasheet table, row Tensile modulus (拉伸模量)
- benchmark: tensile_yield_strength
label: Yield stress, Hostaform C 13021 FC (copolymer)
value: 64
unit: MPa
scope: material
conditions:
grade: Hostaform C 13021 FC, POM copolymer
test: ISO 527 as printed
method: ISO 527, as printed on the datasheet
status: ground
source: mdc-hostaform-c13021fc
where: Datasheet table, row Yield stress (屈服应力)
- benchmark: nominal_strain_at_break
label: Nominal strain at break, Hostaform C 13021 FC (copolymer)
value: 30
unit: '%'
scope: material
conditions:
grade: Hostaform C 13021 FC, POM copolymer
test: ISO 527 as printed
method: ISO 527, as printed on the datasheet
status: ground
source: mdc-hostaform-c13021fc
where: Datasheet table, row Nominal strain at break (名义断裂伸长率)
- benchmark: charpy_notched_impact
label: Charpy notched impact strength at +23 °C, Hostaform C 13021 FC
value: 6
unit: kJ/m2
scope: material
conditions:
grade: Hostaform C 13021 FC, POM copolymer
temperature: +23 °C
notch: type A, as printed
method: ISO 179/1eA, as printed on the datasheet
status: ground
source: mdc-hostaform-c13021fc
where: Datasheet table, row Charpy impact, +23°C (简支梁缺口冲击强度)
- benchmark: atomic_oxygen_erosion_yield
label: Atomic oxygen erosion yield, POM (MISSE 2)
value: 9.14e-24
unit: cm3/atom
scope: material
conditions:
platform: ISS, MISSE 2 PEC 2 tray 1, low Earth orbit
fluence: 8.43e21 atoms/cm2
duration: 3.95 years
method: Measured on MISSE 2 flight samples and listed in NASA TM-2008-215490
status: flight
source: nasa-tm-2008-215490
where: Table I, MISSE 2 PEACE polymers erosion yield data (passport misse2-pom-delrin)
- benchmark: density
label: Density, Delrin 500P NC010 (homopolymer)
value: 1.42
unit: g/cm³
scope: material
conditions:
grade: Delrin 500P NC010, POM homopolymer
temperature: not printed
method: ISO 1183, as printed on the DuPont datasheet
status: ground
source: dupont-delrin-500p
where: Physical table, row Density
- benchmark: melting_point
label: Melting temperature, Delrin 500P NC010 (homopolymer)
value: 178
unit: °C
scope: material
conditions:
grade: Delrin 500P NC010, POM homopolymer
method: ISO 11357-3, as printed on the datasheet
status: ground
source: dupont-delrin-500p
where: Thermal table, row Melting Temperature
- benchmark: tensile_modulus
label: Tensile modulus, Delrin 500P NC010 (homopolymer)
value: 3100
unit: MPa
scope: material
conditions:
grade: Delrin 500P NC010, POM homopolymer
test: ISO 527-2 as printed
method: ISO 527-2, as printed on the datasheet
status: ground
source: dupont-delrin-500p
where: Mechanical table, row Tensile Modulus
- benchmark: tensile_yield_strength
label: Tensile stress at yield, Delrin 500P NC010 (homopolymer)
value: 71
unit: MPa
scope: material
conditions:
grade: Delrin 500P NC010, POM homopolymer
test: ISO 527-2 as printed
method: ISO 527-2, as printed on the datasheet
status: ground
source: dupont-delrin-500p
where: Mechanical table, row Tensile Stress (Yield)
- benchmark: nominal_strain_at_break
label: Nominal tensile strain at break, Delrin 500P NC010 (homopolymer)
value: 30
unit: '%'
scope: material
conditions:
grade: Delrin 500P NC010, POM homopolymer
test: ISO 527-2 as printed
method: ISO 527-2, as printed on the datasheet
status: ground
source: dupont-delrin-500p
where: Mechanical table, row Nominal Tensile Strain at Break
- benchmark: flexural_modulus
label: Flexural modulus, Delrin 500P NC010 (homopolymer)
value: 3000
unit: MPa
scope: material
conditions:
grade: Delrin 500P NC010, POM homopolymer
method: ISO 178, as printed on the datasheet
status: ground
source: dupont-delrin-500p
where: Mechanical table, row Flexural Modulus
- benchmark: charpy_notched_impact
label: Charpy notched impact strength at 23 °C, Delrin 500P NC010 (homopolymer)
value: 9
unit: kJ/m2
scope: material
conditions:
grade: Delrin 500P NC010, POM homopolymer
temperature: 23 °C (73 °F)
notch: type A, ISO 179/1eA
method: ISO 179/1eA, as printed on the datasheet
status: ground
source: dupont-delrin-500p
where: Impact table, Charpy Notched Impact Strength, 73°F (23°C) row
- benchmark: heat_deflection_temperature
label: Heat deflection temperature at 1.8 MPa (unannealed), Delrin 500P NC010
value: 95
unit: °C
scope: material
conditions:
grade: Delrin 500P NC010, POM homopolymer
load: 264 psi (1.8 MPa), unannealed
method: ISO 75-2/A, as printed on the datasheet
status: ground
source: dupont-delrin-500p
where: Thermal table, Heat Deflection Temperature, 264 psi (1.8 MPa), Unannealed row
- benchmark: vicat_softening_temperature
label: Vicat softening temperature, Delrin 500P NC010
value: 155
unit: °C
scope: material
conditions:
grade: Delrin 500P NC010, POM homopolymer
method_load: ISO 306/B50
method: ISO 306/B50, as printed on the datasheet
status: ground
source: dupont-delrin-500p
where: Thermal table, row Vicat Softening Temperature
- benchmark: cte
label: Coefficient of linear thermal expansion, flow direction, Delrin 500P NC010
value: 0.0001
unit: cm/cm/°C
scope: material
conditions:
grade: Delrin 500P NC010, POM homopolymer
direction: flow
method: ISO 11359-2, as printed on the datasheet (printed as 1.0E-4 cm/cm/°C)
status: ground
source: dupont-delrin-500p
where: Thermal table, CLTE, Flow row (SI column)
corrosion:
- environment: Chlorine gas and bleaching fluid
headline: Chlorine attacks acetal at 3 to 5 ppm and higher, so long-term continuous exposure is not recommended.
effect: DuPont states that DELRIN acetal resin is attacked by chlorine at concentrations of 3 to 5 ppm and higher, and is not recommended for long term continuous exposure at these concentrations. Its rating table marks chlorine gas and 10 percent bleaching fluid as unsatisfactory.
rating: severe
conditions:
basis: unstressed specimens in continuous exposure; rating table at ambient temperature
source: dupont-delrin-design-guide
where: 'Chapter 7 (Effects), Resistance to chemicals: zinc chloride and chlorine section; rating table'
- environment: Zinc chloride, and salt water in contact with zinc-plated steel
headline: Zinc chloride depolymerises acetal; salt water alone does not affect it.
effect: DuPont says zinc chloride acts to depolymerise (corrode) DELRIN acetal resin, with attack depending on stress, temperature, concentration and time. Salt water alone does not affect it, but salt water with zinc-plated steel can give a slower effect similar to zinc chloride.
rating: moderate
conditions:
basis: stress, temperature, concentration and time are not quantified in the guide
source: dupont-delrin-design-guide
where: 'Chapter 7 (Effects), Resistance to chemicals: zinc chloride and chlorine section'
- environment: Strong acids and strong bases; steam and hot water
headline: Service life is reduced by lengthy use in steam, hot water, strong acids or strong bases.
effect: DuPont lists steam, hot water, strong acids and strong bases as reducing service life. Its rating table marks hydrochloric acid (10 percent), sulphuric acid (30 percent), nitric acid (10 percent), perchloric acid (10 percent) and phosphoric acid (30 percent) as unsatisfactory, and acetic acid (5 percent) as resistant.
rating: moderate
conditions:
basis: unstressed specimens at ambient temperature; the guide says intermittent exposure and service stresses can change the result
source: dupont-delrin-design-guide
where: Introduction, service life statement; Chapter 7 rating table
- environment: Hot water and strong caustic or high pH solutions, copolymer against homopolymer
headline: Copolymer acetal resists hot water and strong caustics better than homopolymer, per Alro.
effect: Alro lists better resistance to hot water and strong caustics, or high pH solutions, as an advantage of acetal copolymer over homopolymer. No temperature, concentration or time is printed.
rating: low
conditions:
basis: comparison of copolymer and homopolymer, no test figures printed
source: alro-acetal-catalog
where: Acetal section, list of advantages of copolymer over homopolymer
- environment: Sunlight UV (290 to 400 nm), outdoors and through glass
headline: Acetal is affected by sunlight; UV-stabilised grades are offered for outdoor and glass-behind use.
effect: DuPont says acetal resins, like most polymers, are affected by light, particularly sunlight with ultraviolet radiation of 290 to 400 nm. It lists UV-stabilised grades (for example DELRIN 127UV, 527UV and 927UV) with excellent UV resistance and thermal stability, and says the x27UV series suits parts exposed to sunlight through glass. No retention figure is printed.
rating: moderate
conditions:
wavelength: 290 to 400 nm
basis: grade dependent; no dose or retention figure printed
source: dupont-delrin-design-guide
where: Chapter 7 (Effects), Weathering section; grade list
- environment: Gamma radiation
headline: DuPont gives depolymerisation as the predominant degradation mode under gamma ray dosage.
effect: DuPont says that the predominant mode of degradation resulting from gamma ray dosage is depolymerisation. The guide prints no dose figure in the text read.
rating: moderate
conditions:
dose: not printed in the text read
source: dupont-delrin-design-guide
where: Chapter 7 (Effects), Exposure to high energy radiation section
- environment: Unstressed exposure in air at 60 C, long term
headline: DELRIN 500 keeps a tensile strength above 55 MPa for about 5 years at 60 C.
effect: DuPont's long-term exposure curve for unstressed injection-moulded bars in air says DELRIN 500 would keep a tensile strength in excess of 55 MPa for approximately 5 years at 60 C.
rating: low
conditions:
temperature: 60 C
stress: none, unstressed
grade: DELRIN 500
source: dupont-delrin-design-guide
where: Chapter 7 (Effects), Exposure in air at elevated temperature, Figure 7.02 text
- environment: 'Fuels: M-15 gasoline (15 percent methanol) and diesel at 60 C'
headline: Standard grades change only slightly after 1500 h in M-15 and hardly at all in diesel.
effect: DuPont aged DELRIN 500 and 500P NC010 for up to 1500 hours at 60 C in M-15, and reports only small changes from slight plastification by fuel absorption. In diesel, bio-diesel and kerosene it reports almost no change in dimensional or mechanical properties after 2000 hours at 60 C.
rating: low
conditions:
temperature: 60 C
time: up to 1500 h in M-15; up to 2000 h in diesel
fuel: M-15 is regular gasoline with 15 percent methanol
source: dupont-delrin-design-guide
where: 'Chapter 7 (Effects), Resistance to chemicals: fuels section; Figure 7.01'
risks:
hazards:
- text: 'Formaldehyde (CAS 50-00-0), the monomer POM is made from. PubChem aggregated GHS: Danger, with H302 harmful if swallowed, H314 causes severe skin burns and eye damage, H317 may cause an allergic skin reaction, H330 fatal if inhaled, H341 suspected of causing genetic defects and H350 may cause cancer. The POM polymer itself has no GHS entry in PubChem.'
ghs:
- H302
- H314
- H317
- H330
- H341
- H350
source: pubchem-formaldehyde
where: Safety and Hazards, GHS Classification (aggregated, CID 712)
failure_risks:
- mode: Atomic oxygen erosion in low Earth orbit
trigger: Exposure of a POM part to atomic oxygen in low Earth orbit, as on the MISSE 2 flight
consequence: Surface erosion at a yield of 9.14e-24 cm3/atom as measured on MISSE 2
severity: moderate
source: nasa-tm-2008-215490
where: Table I
- mode: Chlorine attack
trigger: Chlorine gas or bleach at 3 to 5 ppm and higher, in long-term continuous exposure
consequence: Attack on the acetal; DuPont rates chlorine gas and 10 percent bleaching fluid as unsatisfactory
severity: critical
source: dupont-delrin-design-guide
where: Chapter 7, Zinc chloride and chlorine; rating table
- mode: Zinc chloride depolymerisation
trigger: Zinc chloride, or salt water in contact with zinc-plated steel
consequence: Depolymerisation (corrosion) of the acetal, depending on stress, temperature, concentration and time
severity: moderate
source: dupont-delrin-design-guide
where: Chapter 7, Zinc chloride and chlorine
- mode: Strong acid or strong base attack
trigger: Lengthy use in strong acids or strong bases, or in steam and hot water
consequence: Shorter service life; DuPont rates hydrochloric, sulphuric, nitric and phosphoric acids at 10 to 30 percent as unsatisfactory
severity: moderate
source: dupont-delrin-design-guide
where: Introduction, service life statement; Chapter 7 rating table
- mode: UV degradation in sunlight
trigger: Sunlight UV at 290 to 400 nm on standard grades, outdoors or through glass
consequence: Light-induced degradation; UV-stabilised grades are offered for this exposure
severity: moderate
source: dupont-delrin-design-guide
where: Chapter 7, Weathering section
- mode: Gamma radiation depolymerisation
trigger: Gamma ray dosage
consequence: DuPont gives depolymerisation as the predominant degradation mode
severity: moderate
source: dupont-delrin-design-guide
where: Chapter 7, Exposure to high energy radiation
side_effects: []
handling:
- text: Keep chlorine, bleach and chlorinated water away from stressed parts. DuPont does not recommend long-term continuous exposure at 3 to 5 ppm chlorine and above.
source: dupont-delrin-design-guide
where: Chapter 7, Zinc chloride and chlorine
- text: Use local extraction where heating or processing may release formaldehyde; the formaldehyde GHS codes above are the reason. No POM-specific release figure was read.
source: pubchem-formaldehyde
where: Safety and Hazards, GHS Classification
mitigations:
- text: For sunlight exposure, choose a UV-stabilised grade such as DELRIN 127UV, 527UV or 927UV, per the DuPont grade list.
source: dupont-delrin-design-guide
where: Grade list
- text: For hot water or strong caustic service, choose a copolymer grade, which Alro says resists these better than homopolymer.
source: alro-acetal-catalog
where: Acetal section, copolymer advantages
uses:
- application: mechanisms
device: Gears and drive trains
example: DuPont lists DELRIN 100 for high performance engineering parts such as gears, and DELRIN 500CL for gears, drive trains and sliding devices. Alro lists gears and pulleys among its acetal applications.
source: dupont-delrin-design-guide
where: Grade list, DELRIN 100 and DELRIN 500CL rows
- application: mechanisms
device: Zippers and thin-section parts
example: DuPont lists DELRIN 900P, a low-viscosity grade for thin sections, for consumer electronics parts and zippers.
source: dupont-delrin-design-guide
where: Grade list, DELRIN 900P row
- application: structures
device: Fasteners and snap-fits
example: DuPont lists DELRIN 500 for general mechanical parts, automotive fuel systems, snap-fits, fasteners and gears, and DELRIN 100T for fasteners, seat belt restraint systems and gears.
source: dupont-delrin-design-guide
where: Grade list, DELRIN 500 and DELRIN 100T rows
supply:
- subject: Formaldehyde, the feedstock for POM
routes: PubChem states that formaldehyde is prepared commercially by catalytic vapour-phase oxidation of methanol with air, over heated silver, copper, alumina or coke, and that the silver, copper or iron-molybdenum oxide processes are the widely used ones. It also states that all of the world's commercial formaldehyde is made from methanol and air by a metal or metal-oxide catalyst process.
producers: []
critical_lists: []
source: pubchem-formaldehyde
where: Methods of Manufacturing
- subject: POM resin, made by polymerisation of formaldehyde
routes: DuPont says acetal is made by the polymerization of formaldehyde. Celanese developed the copolymer route, which Polyplastics (Daicel) marketed as DURACON from 1964.
producers:
- name: Polyplastics (Daicel)
note: DURACON polyacetal. Founded in 1964 as a joint venture with Celanese; Daicel made it a wholly owned subsidiary in October 2020.
country: Polyplastics (Daicel)
- name: Celanese
note: Hostaform copolymer grades, as printed on the Material Data Center datasheets read for this profile.
country: Celanese
- name: DuPont
note: Delrin homopolymer, as printed on the DuPont Delrin 500P NC010 datasheet read for this profile.
country: DuPont
critical_lists: []
source: daicel-history
where: Corporate history, 1964 and October 2020 entries
documents:
- title: Hostaform C 2521, Material Data Center datasheet
type: datasheet
url: https://materialdatacenter.com/ms/en/Hostaform/Celanese/HOSTAFORM%C2%AE+C+2521/e3040fc5/2434
- title: Hostaform C 13021 FC, Material Data Center datasheet
type: datasheet
url: https://materialdatacenter.com/ms/zh/Hostaform/Celanese/HOSTAFORM%C2%AE+C+13021+FC/9f8f323b/2434
- title: Polyoxymethylene, Wikipedia
type: report
url: https://en.wikipedia.org/wiki/Polyoxymethylene
- title: Delrin 500P NC010, DuPont technical data sheet (PDF, via Protolabs)
type: datasheet
url: https://Protolabs.com/media/1022598/delrin-500p_nc010.pdf
- title: Banks, Backus and de Groh, Atomic Oxygen Erosion Yield Predictive Tool for Spacecraft Polymers in Low Earth Orbit, NASA/TM-2008-215490
type: report
url: https://ntrs.nasa.gov/citations/20090011780
year: 2008
- title: PubChem, Formaldehyde CID 712 (GHS and manufacture)
type: database
url: https://pubchem.ncbi.nlm.nih.gov/compound/712
- title: DELRIN acetal resin design information, DuPont
type: datasheet
url: https://www.spacematdb.com/spacemat/manudatasheets/Delrin%20design%20info.pdf
- title: Delrin acetal homopolymer technical data sheet
type: datasheet
url: https://laminatedplastics.com/delrin.pdf
- title: Alro Plastics acetal section
type: datasheet
url: https://www.alro.com/Resources/WebResources/AlroCom/PlasticsReferanceCatalog/PDFs/002-Acetals.pdf
- title: DAICEL corporate history
type: report
url: https://www.daicel.com/en/corporate/history/
gaps:
- Delrin 500P NC010 values are from a DuPont datasheet PDF hosted by Protolabs (not the DuPont site); the Nordson-hosted and plasticker copies seen in search were not read, so their different figures are not used.
- 'Supply volumes: no POM or formaldehyde production volume or country share was read. Producer names come from the Daicel history page and the Material Data Center datasheets. Asahi Kasei, BASF, Mitsubishi Gas Chemical and others named in market-report snippets are not verified and are not listed.'
- 'Ageing: no temperature, rate or formaldehyde figure for thermal degradation of POM was read. The DuPont guide names depolymerisation only for zinc chloride and gamma dose.'
- 'Corrosion: DuPont gives qualitative ratings and some time-based data only. The Celanese Hostaform product manual and Celcon design guide returned HTML rather than readable PDF, so no Celanese chemical table is used.'
- 'Hazards: PubChem has no record for polyoxymethylene. Lookups by name and by CAS 9002-81-7 returned not found, so no POM GHS entry is recorded. The hazards above are for formaldehyde.'
- 'Uses: only DuPont grade-list uses and one Alro line are recorded. No sourced use for POM in space was read.'
- No Delrin homopolymer grade other than 500P NC010 has a datasheet value in this profile. The DuPont design guide and Delrin technical data sheet give qualitative statements for other grades.
- Flexural modulus, HDT and Izod impact are not printed on the C 13021 FC datasheet read, and flexural modulus is not printed on C 2521.
- No outgassing, total mass loss, UV, radiation or thermal-cycling result for POM in space was read; the passport lists these stresses but gives no values for them.
- Test conditions and standards are as printed on the Material Data Center pages; the Celanese originals were not reached.
sources:
wiki-pom:
title: Polyoxymethylene, Wikipedia (composition and history only)
id: Wikipedia article Polyoxymethylene
url: https://en.wikipedia.org/wiki/Polyoxymethylene
kind: web
license: CC BY-SA 4.0
where: 'Copolymer section: the copolymer replaces about 1–1.5% of the –CH2O– groups with –CH2CH2O–'
dupont-delrin-500p:
title: Delrin 500P NC010, DuPont Performance Polymers technical data sheet
id: DuPont Delrin 500P NC010 product data sheet, hosted by Protolabs
url: https://Protolabs.com/media/1022598/delrin-500p_nc010.pdf
kind: datasheet
license: manufacturer datasheet, linked not reproduced
mdc-hostaform-c2521:
title: Hostaform C 2521, Material Data Center typical properties
id: Material Data Center trade name entry, Celanese Hostaform C 2521
url: https://materialdatacenter.com/ms/en/Hostaform/Celanese/HOSTAFORM%C2%AE+C+2521/e3040fc5/2434
kind: database
license: third-party database page, linked not reproduced
mdc-hostaform-c13021fc:
title: Hostaform C 13021 FC, Material Data Center typical properties
id: Material Data Center trade name entry, Celanese Hostaform C 13021 FC
url: https://materialdatacenter.com/ms/zh/Hostaform/Celanese/HOSTAFORM%C2%AE+C+13021+FC/9f8f323b/2434
kind: database
license: third-party database page, linked not reproduced
nasa-tm-2008-215490:
title: Atomic Oxygen Erosion Yield Predictive Tool for Spacecraft Polymers in Low Earth Orbit
id: NASA/TM-2008-215490 (Banks, Backus and de Groh, 2008), NTRS 20090011780
url: https://ntrs.nasa.gov/citations/20090011780
year: 2008
kind: report
license: NASA public document
pubchem-formaldehyde:
title: 'Formaldehyde (CID 712), PubChem compound record: GHS classification and methods of manufacture'
id: PubChem CID 712, formaldehyde, CAS 50-00-0 (read via the PubChem REST pug_view API)
url: https://pubchem.ncbi.nlm.nih.gov/compound/712
kind: database
license: public database record, linked not reproduced
dupont-delrin-design-guide:
title: DELRIN acetal resin design information, DuPont (chemical resistance, weathering, grade list)
id: DuPont DELRIN design information PDF, hosted at spacematdb.com
url: https://www.spacematdb.com/spacemat/manudatasheets/Delrin%20design%20info.pdf
kind: handbook
license: manufacturer design guide, linked not reproduced
delrin-tds-laminatedplastics:
title: Delrin (acetal homopolymer) POM technical data sheet
id: Delrin acetal homopolymer technical data sheet, hosted on laminatedplastics.com
url: https://laminatedplastics.com/delrin.pdf
kind: datasheet
license: manufacturer datasheet, linked not reproduced
alro-acetal-catalog:
title: Acetal copolymer and homopolymer, Alro Plastics catalogue section
id: Alro Plastics plastics reference catalogue, acetal section (PDF)
url: https://www.alro.com/Resources/WebResources/AlroCom/PlasticsReferanceCatalog/PDFs/002-Acetals.pdf
kind: web
license: distributor catalogue, linked not reproduced
daicel-history:
title: 'DAICEL corporate history: Polyplastics joint venture (1964) and wholly owned subsidiary (2020)'
id: DAICEL company history page
url: https://www.daicel.com/en/corporate/history/
kind: web
license: company web page, linked not reproduced
license: CC-BY-4.0
updated: '2026-10-18'
review:
status: draft
method: assistant
checked_values: 24
unreachable: 4
caveats: 5
note: 'Values were read by an AI assistant on 2026-10-18. The two copolymer grades were read from Material Data Center pages (third-party, not Celanese originals). The erosion yield was copied from the passport misse2-pom-delrin, which was verified by hand. Unreachable: Delrin 500P, 500T and 500CPE pages on Material Data Center (404), Celanese datasheets (403/404), CURBELL acetal page (403). Caveats: no Delrin homopolymer value is recorded; the copolymer values are for Hostaform grades, not Delrin; the erosion yield is for one flight sample; source count is 10 (see sources).'
story:
recipe:
line: Polyoxymethylene is a chain of repeating CH2O units, made from formaldehyde. The homopolymer is end-capped to stabilise it; the copolymer contains about 1 to 1.5 percent CH2CH2O units along the chain (Wikipedia, composition only; key wiki-pom).
parts:
- name: Carbon
symbol: C
atoms: 1
atomic_weight: 12.011
role: One carbon per CH2O repeat unit, part of the backbone.
- name: Hydrogen
symbol: H
atoms: 2
atomic_weight: 1.008
role: Two hydrogens per CH2O repeat unit.
- name: Oxygen
symbol: O
atoms: 1
atomic_weight: 15.999
role: One ether oxygen per CH2O repeat unit, joining the backbone.
risk_groups:
- title: For people
lead: POM has no GHS entry in PubChem; the hazard here is formaldehyde, the monomer it is made from.
level: 1
verdict: Formaldehyde hazard
points:
- label: Classification
line: Formaldehyde carries H302, H314, H317, H330, H341 and H350 (PubChem aggregated). Chlorine and strong acids are a corrosion risk for parts, not a listed hazard for people.
- title: If it fails
lead: The failure route in these sources is erosion in orbit, measured on one flight sample.
points:
- label: Atomic oxygen
line: On MISSE 2 the erosion yield was 9.14e-24 cm3/atom, from the same NASA report.
uses:
- where: Gears and drive trains
line: DuPont lists DELRIN 100 for gears and DELRIN 500CL for gears, drive trains and sliding devices.
- where: Zippers and thin-section parts
line: DuPont lists DELRIN 900P, a low-viscosity grade for thin sections, for consumer electronics parts and zippers.
- where: Fasteners and snap-fits
line: DuPont lists DELRIN 500 for snap-fits, fasteners and gears, and DELRIN 100T for fasteners and seat belt systems.
why: Polyoxymethylene is a semicrystalline engineering thermoplastic. The two Hostaform copolymer grades read here have a density of 1410 kg/m3 and melting temperatures of 165 °C (C 2521) and 166 °C (C 13021 FC) at 10 °C/min. Their tensile moduli are 2600 MPa and 2700 MPa.
can_do:
- label: Stiff moulding grade
value: 2700 MPa tensile modulus
benchmark: tensile_modulus
line: Hostaform C 13021 FC has a tensile modulus of 2700 MPa and a yield stress of 64 MPa under ISO 527, as printed on its datasheet page.
- label: Heat under load
value: 101 °C HDT at 1.80 MPa
benchmark: heat_deflection_temperature
line: Hostaform C 2521 has a temperature of deflection under load of 101 °C at 1.80 MPa, ISO 75-1/-2, as printed on its datasheet page.
- label: Survive in orbit
value: 9.14e-24 cm3/atom
benchmark: atomic_oxygen_erosion_yield
line: NASA lists a MISSE 2 erosion yield for polyoxymethylene of 9.14e-24 cm3/atom, in Table I.
compare: The two grades are read from one database, so compare the rows as examples for these two Hostaform grades, not as a ranking of all POM.
compare_rows:
- scope: material
label: Density
benchmark: density
- scope: material
label: Melting temperature
benchmark: melting_point
- scope: material
label: Tensile modulus
benchmark: tensile_modulus
handling:
- 'Specify the grade: the two copolymer grades read differ in modulus and melting temperature.'
- Treat the datasheet values as typical values as printed, not as specification limits.
good_for:
- 'Stiff moulded parts: 2700 MPa tensile modulus and 64 MPa yield stress in Hostaform C 13021 FC, as printed.'
- 'Known atomic oxygen behaviour: 9.14e-24 cm3/atom on MISSE 2 in low Earth orbit.'
watch_out:
- Atomic oxygen erodes POM at 9.14e-24 cm3/atom, so exterior use needs protection or a rate allowance.
- No Delrin homopolymer value was read, so the numbers here are for copolymer grades only.
- Flexural modulus and Izod impact were not found on the datasheets read.
verdict: 'Polyoxymethylene is a stiff engineering plastic: the two copolymer grades read have a density of 1410 kg/m3, a melting temperature of 165 to 166 °C, and a tensile modulus of 2600 to 2700 MPa. Its MISSE 2 erosion yield of 9.14e-24 cm3/atom is recorded, and no homopolymer Delrin data is in this profile yet.'
References
Every number above carries a reference number. Click one to see the source and where in it the value comes from.
| # | Source | Type | Year | Used for |
|---|---|---|---|---|
| Polyoxymethylene, Wikipedia (composition and history only) | web | 0 values | ||
| Delrin 500P NC010, DuPont Performance Polymers technical data sheet | datasheet | 10 values | ||
| Hostaform C 2521, Material Data Center typical properties | database | 7 values | ||
| Hostaform C 13021 FC, Material Data Center typical properties | database | 6 values | ||
| Atomic Oxygen Erosion Yield Predictive Tool for Spacecraft Polymers in Low Earth Orbit | report | 2008 | 3 values | |
| Formaldehyde (CID 712), PubChem compound record: GHS classification and methods of manufacture | database | 3 values | ||
| DELRIN acetal resin design information, DuPont (chemical resistance, weathering, grade list) | handbook | 17 values | ||
| Delrin (acetal homopolymer) POM technical data sheet | datasheet | 0 values | ||
| Acetal copolymer and homopolymer, Alro Plastics catalogue section | web | 2 values | ||
| DAICEL corporate history: Polyplastics joint venture (1964) and wholly owned subsidiary (2020) | web | 1 value |