spore: profile
id: uhmwpe
spore_version: 0.2
family: polyolefins
name: Ultra-high-molecular-weight polyethylene
abbreviation: UHMWPE
role: wear-resistant engineering plastic and high-strength fibre (Dyneema, Spectra)
category: polymers
type: polyolefins
summary: |
  UHMWPE is polyethylene with a molar mass of about 2 to 6 million daltons. It is sold as moulded or extruded sheet and as gel-spun fibre, under trade names such as Dyneema and Spectra. A natural TIVAR 1000 sheet grade has a density of 0.930 g/cc, a tensile strength of 40.0 MPa and an elongation at break of 300 %, with a melting peak of 135 °C (ASTM D3418). Gel-spun fibre is quoted with a yield strength as high as 2.4 GPa. A 2022 study of a UHMWPE fibre barrier net found that UV ageing cut its breaking strength faster than salt spray or damp heat.
best_for: Low-friction, abrasion-resistant parts, and high-strength fibre at about 0.97 g/cm3
weakest_at: 'Heat and sunlight: a 82.2 °C long-term air limit for the sheet grade, and UV ageing that breaks polymer chains'
identity:
  formula: (C2H4)n, ultra-high-molecular-weight polymer of ethylene, 2 to 6 million daltons
  cas: 9002-88-4
  source: tivar-vmx-sds
  where: Section 3 (Composition), row Polyethylene, CAS 9002-88-4 (food-grade UHMW-PE SDS). Molar mass range from the Wikipedia UHMWPE article.
tags:
  environments: []
  stresses:
    - extreme-cold
    - extreme-heat
  applications:
    - structures
    - mechanisms
    - radiation-shielding
properties:
  - benchmark: density
    label: Density, TIVAR 1000 natural UHMW-PE sheet
    value: 0.93
    unit: g/cc
    scope: material
    conditions:
      grade: TIVAR 1000, natural (colours not included on the sheet)
      temperature: not stated
    method: ASTM D792, as printed on the datasheet
    status: ground
    source: tivar-1000-datasheet
    where: Physical Properties table, row Specific Gravity
  - benchmark: density
    label: Density, UHMWPE in general (typical range)
    value: 0.93
    value_high: 0.94
    unit: g/cm3
    scope: material
    conditions:
      basis: typical range for UHMWPE as stated in the article; no grade or test standard printed
    method: Stated in a Wikipedia article (secondary source)
    status: ground
    source: wiki-uhmwpe
    where: Properties section, density sentence
  - benchmark: density
    label: Density, gel-spun UHMWPE fibre (Dyneema SK75)
    value: 0.97
    bound: lower
    unit: g/cm3
    scope: material
    conditions:
      form: gel-spun fibre, grade named in the article as Dyneema SK75
      temperature: not stated
    method: Stated in a Wikipedia article (secondary source); the article says "as low as"
    status: ground
    source: wiki-uhmwpe
    where: Properties section, density sentence (fibre)
  - benchmark: ultimate_tensile_strength
    label: Tensile strength, TIVAR 1000 natural UHMW-PE sheet
    value: 40
    unit: MPa
    scope: material
    conditions:
      grade: TIVAR 1000, natural
      temperature: not stated
      note: The datasheet says the material has no yield point, so this is the tensile strength.
    method: ASTM D638, as printed on the datasheet
    status: ground
    source: tivar-1000-datasheet
    where: Mechanical Properties table, row Tensile Strength
  - benchmark: yield_strength
    label: Tensile yield strength, UHMWPE (typical values)
    value: 19.3
    value_high: 23
    unit: MPa
    scope: material
    conditions:
      form: moulded or extruded UHMWPE, typical values
      test: not stated
    method: Stated in a Wikipedia article (secondary source)
    status: ground
    note: The TIVAR 1000 datasheet gives no yield point for its grade; this range comes from the article only.
    source: wiki-uhmwpe
    where: Mechanical properties sentence (typical tensile yield strength)
  - benchmark: yield_strength
    label: Yield strength, gel-spun UHMWPE fibre (as high as)
    value: 2.4
    bound: upper
    unit: GPa
    scope: material
    conditions:
      form: gel-spun fibre (grade not named in the article)
      basis: the article reports yield strength, not tensile strength
    method: Stated in a Wikipedia article (secondary source); the article says "as high as"
    status: ground
    source: wiki-uhmwpe
    where: Gel spinning and fibre section, strength sentence
  - benchmark: elongation
    label: Elongation at break, TIVAR 1000 natural UHMW-PE sheet
    value: 300
    unit: '%'
    scope: material
    conditions:
      grade: TIVAR 1000, natural
      temperature: not stated
    method: ASTM D638, as printed on the datasheet
    status: ground
    source: tivar-1000-datasheet
    where: Mechanical Properties table, row Elongation at Break
  - benchmark: elongation
    label: Elongation at break, UHMWPE (typical range)
    value: 250
    value_high: 450
    unit: '%'
    scope: material
    conditions:
      basis: typical range stated in the article; grade and test standard not printed
    method: Stated in a Wikipedia article (secondary source)
    status: ground
    source: wiki-uhmwpe
    where: Mechanical properties sentence (elongation at break)
  - benchmark: elastic_modulus
    label: Tensile modulus, TIVAR 1000 natural UHMW-PE sheet
    value: 0.552
    unit: GPa
    scope: material
    conditions:
      grade: TIVAR 1000, natural
      temperature: not stated
    method: ASTM D638, as printed on the datasheet
    status: ground
    source: tivar-1000-datasheet
    where: Mechanical Properties table, row Tensile Modulus
  - benchmark: flexural_strength
    label: Flexural strength, TIVAR 1000 natural UHMW-PE sheet
    value: 24.1
    unit: MPa
    scope: material
    conditions:
      grade: TIVAR 1000, natural
      temperature: not stated
    method: ASTM D790, as printed on the datasheet
    status: ground
    source: tivar-1000-datasheet
    where: Mechanical Properties table, row Flexural Strength
  - benchmark: flexural_modulus
    label: Flexural modulus, TIVAR 1000 natural UHMW-PE sheet
    value: 0.6
    unit: GPa
    scope: material
    conditions:
      grade: TIVAR 1000, natural
      temperature: not stated
    method: ASTM D790, as printed on the datasheet
    status: ground
    source: tivar-1000-datasheet
    where: Mechanical Properties table, row Flexural Modulus
  - benchmark: coefficient_of_friction
    label: Dynamic coefficient of friction, TIVAR 1000 against steel
    value: 0.12
    unit: '-'
    scope: material
    conditions:
      contact: dry, against steel
      grade: TIVAR 1000, natural
    method: QTM55007, as printed on the datasheet
    status: ground
    source: tivar-1000-datasheet
    where: Mechanical Properties table, row Coefficient of Friction, Dynamic
  - benchmark: melting_point
    label: Melting point, TIVAR 1000 (crystalline peak)
    value: 135
    unit: °C
    scope: material
    conditions:
      basis: crystalline peak
      grade: TIVAR 1000, natural
    method: ASTM D3418, as printed on the datasheet
    status: ground
    source: tivar-1000-datasheet
    where: Thermal Properties table, row Melting Point
  - benchmark: melting_point
    label: Melting point onset, gel-spun UHMWPE fibre
    value: 127.7
    unit: °C
    scope: material
    conditions:
      form: fibre (grade not named in the article)
      basis: melting point onset, as stated
    method: Stated in a Wikipedia article (secondary source); test method not printed
    status: ground
    source: wiki-uhmwpe
    where: Thermal properties sentence (melting point onset)
  - benchmark: max_service_temp
    label: Maximum service temperature in air, TIVAR 1000 (long term)
    value: 82.2
    unit: °C
    scope: material
    conditions:
      environment: air
      duration: long term
      grade: TIVAR 1000, natural
    method: Datasheet rating, as printed
    status: ground
    source: tivar-1000-datasheet
    where: Thermal Properties table, row Maximum Service Temperature, Air
  - benchmark: max_service_temp
    label: Long-term service limit, UHMWPE fibre (article advice)
    value: 90
    bound: upper
    unit: °C
    scope: material
    conditions:
      form: fibre
      duration: long periods; the article says not advisable to exceed this for long periods
    method: Stated in a Wikipedia article (secondary source)
    status: ground
    source: wiki-uhmwpe
    where: Thermal properties sentence (fibre, 90 °C)
  - benchmark: heat_deflection_temperature
    label: Heat deflection temperature, TIVAR 1000 at 1.8 MPa
    value: 46.7
    unit: °C
    scope: material
    conditions:
      load: 1.8 MPa (264 psi)
      grade: TIVAR 1000, natural
    method: ASTM D648, as printed on the datasheet
    status: ground
    source: tivar-1000-datasheet
    where: Thermal Properties table, row Deflection Temperature at 1.8 MPa
  - benchmark: thermal_conductivity
    label: Thermal conductivity, TIVAR 1000 natural UHMW-PE sheet
    value: 0.409
    unit: W/m-K
    scope: material
    conditions:
      grade: TIVAR 1000, natural
      temperature: not stated
    method: As printed on the datasheet
    status: ground
    source: tivar-1000-datasheet
    where: Thermal Properties table, row Thermal Conductivity
  - benchmark: cte
    label: Linear coefficient of thermal expansion, TIVAR 1000
    value: 198
    unit: µm/m-°C
    scope: material
    conditions:
      temperature: '-40 to 149 °C'
      grade: TIVAR 1000, natural
    method: ASTM E831, as printed on the datasheet
    status: ground
    source: tivar-1000-datasheet
    where: Thermal Properties table, row CTE, linear
  - benchmark: moisture_absorption
    label: Water absorption, TIVAR 1000 (24 h immersion)
    value: 0.01
    bound: upper
    unit: '%'
    scope: material
    conditions:
      immersion: 24 h
      basis: printed as <= 0.010 %
      grade: TIVAR 1000, natural
    method: ASTM D570, as printed on the datasheet
    status: ground
    source: tivar-1000-datasheet
    where: Physical Properties table, row Water Absorption
  - benchmark: dielectric_constant
    label: Dielectric constant, TIVAR 1000
    value: 2.3
    unit: '-'
    scope: material
    conditions:
      frequency: 1e6 Hz
      grade: TIVAR 1000, natural
    method: ASTM D150, as printed on the datasheet
    status: ground
    source: tivar-1000-datasheet
    where: Electrical Properties table, row Dielectric Constant
  - benchmark: dielectric_strength
    label: Dielectric strength, TIVAR 1000 (short term)
    value: 90.6
    unit: kV/mm
    scope: material
    conditions:
      duration: short term
      grade: TIVAR 1000, natural
    method: ASTM D149, as printed on the datasheet
    status: ground
    source: tivar-1000-datasheet
    where: Electrical Properties table, row Dielectric Strength
  - benchmark: dissipation_factor
    label: Dissipation factor, TIVAR 1000
    value: 0.0005
    unit: '-'
    scope: material
    conditions:
      frequency: 1e6 Hz
      grade: TIVAR 1000, natural
    method: ASTM D150, as printed on the datasheet
    status: ground
    source: tivar-1000-datasheet
    where: Electrical Properties table, row Dissipation Factor
  - benchmark: flash_point
    label: Flash point, food-grade TIVAR VMX UHMW-PE (SDS)
    value: 662
    bound: lower
    unit: °F
    scope: material
    conditions:
      product: TIVAR VMX food-grade UHMW-PE (SDS for the grade; not a datasheet value for TIVAR 1000)
      method: not stated on the SDS
    method: As printed on the SDS (printed as >662°F)
    status: ground
    source: tivar-vmx-sds
    where: Physical and chemical properties table (Section 9), row Flash Point
corrosion:
  - environment: Ultraviolet light and sunlight
    headline: UV ageing breaks polymer chains and cut a fibre net's breaking strength faster than salt spray or damp heat.
    effect: In a 2022 study of a UHMWPE fibre barrier net, the authors say UV energy activates UHMWPE molecules and causes chain breaking, and that breaking strength fell faster under UV than under salt spray or hygrothermal ageing. The UV curve is shown in a figure, and the text gives no UV retention number.
    rating: moderate
    conditions:
      basis: qualitative statement and figure; UV irradiance, lamp type and exposure time are not stated in the text read
      specimen: UHMWPE fibre barrier net, not moulded sheet
    source: mdpi-barrier-net
    where: Results (Figure 9c, UV panel) and conclusion (1)
  - environment: UV ageing of a UHMWPE/HDPE blend (80/20)
    headline: In an 80/20 HDPE/UHMWPE monofilament blend, the carbonyl and unsaturation indices after 600 h of UV were about 55 % and 40 % of those of pure HDPE.
    effect: A 2026 paper aged pure HDPE and an 80/20 HDPE/UHMWPE monofilament under UVA-340 lamps (ISO 4892-3, ASTM G154) for up to 600 h. The authors report that surface cracks in the blend were significantly fewer and smaller than in pure HDPE after 600 h. This is a blend with a low UHMWPE share, so it indicates a trend and not a value for pure UHMWPE.
    rating: moderate
    conditions:
      basis: 80/20 wt% HDPE/UHMWPE blend, UVA-340 lamp, ISO 4892-3 and ASTM G154, 0 to 600 h
    source: pmc-blend-uv
    where: Abstract (CI and UI ratios); Results, carbonyl and unsaturation indices (Figure 3)
  - environment: Salt spray and hot humid (hygrothermal) ageing of a fibre net
    headline: Salt spray lowered breaking strength to 655 N after 60 days; hygrothermal ageing took it from 850 N to 703 N in 10 days.
    effect: The same study gives printed breaking strength values for a UHMWPE fibre barrier net. In salt spray it decreased to 655 N after 60 days. In hygrothermal ageing it fell from 850 N to 703 N after 10 days and then rose slightly to 725 N after 30 days, which the authors attribute to fibres bonding into clumps. The authors state that salt spray has a more significant effect than hygrothermal ageing.
    rating: moderate
    conditions:
      specimen: UHMWPE fibre barrier net, breaking strength in N (net specimen, not per fibre)
      exposure: salt spray up to 60 days; hygrothermal up to 30 days; chamber settings not read
    source: mdpi-barrier-net
    where: Results, salt spray and hygrothermal paragraphs (Figure 9a and 9b)
  - environment: Long-term heat in air
    headline: The sheet grade is rated to 82.2 °C long term in air and deflects at 46.7 °C under 1.8 MPa.
    effect: The TIVAR 1000 datasheet gives a long-term maximum service temperature in air of 82.2 °C (180 °F), and a heat deflection temperature of 46.7 °C at 1.8 MPa (ASTM D648). The melting peak is 135 °C. The article says the fibre should not be used above 90 °C for long periods.
    rating: moderate
    conditions:
      basis: datasheet rating and standard test; no ageing time or oxygen level printed
    source: tivar-1000-datasheet
    where: Thermal Properties table (Maximum Service Temperature, Air; Deflection Temperature; Melting Point)
  - environment: Oxidation and radiation processing
    headline: Radiation cross-linking and heat treatment are used to improve oxidation resistance; vitamin E is also used.
    effect: Wikipedia says highly cross-linked UHMWPE is made by gamma or electron-beam radiation at 50 to 105 kGy (5.0 to 10.5 Mrad) and then thermally processed to improve oxidation resistance. It also says vitamin E is used as an antioxidant. The article gives no oxidation rate, time or retained-property figure.
    rating: low
    conditions:
      basis: qualitative statements and processing doses; no ageing test
    source: wiki-uhmwpe
    where: Radiation and oxidation statements in the properties and processing sections
  - environment: Water and humidity
    headline: Water absorption is 0.010 % or less after 24 h immersion.
    effect: The TIVAR 1000 datasheet gives water absorption of 0.010 % or less after 24 h immersion (ASTM D570), and the same value at saturation. Wikipedia describes UHMWPE as very resistant to water and moisture. No ageing time under humid conditions is printed.
    rating: low
    conditions:
      basis: 24 h immersion, ASTM D570, datasheet value
    source: tivar-1000-datasheet
    where: Physical Properties table, rows Water Absorption and Water Absorption at Saturation
  - environment: Chemicals (acids, alkalis, solvents, hydrocarbons)
    headline: Aromatic hydrocarbons are unacceptable; strong acids and ketones or esters are limited; most other chemicals are acceptable.
    effect: The TIVAR 1000 chemical resistance table rates strong acids (pH 1 to 3), ketones and esters, hot water and steam, and continuous sunlight as Limited, and aromatic hydrocarbons as Unacceptable. Weak acids, strong alkalis (pH 11 to 14), chlorinated solvents, aliphatic hydrocarbons and inorganic salt solutions are rated Acceptable. Wikipedia says UHMWPE resists acids, alkalis and many corrosive chemicals except some oxidising acids. No concentration or temperature is printed in either source.
    rating: moderate
    conditions:
      basis: qualitative ratings; no concentration, temperature or time printed
    source: tivar-1000-datasheet
    where: Chemical Resistance Properties table
risks:
  hazards:
    - text: The TIVAR VMX food-grade UHMW-PE SDS gives the GHS classification as None, the signal word as None and the hazard statements as None.
      ghs: []
      source: tivar-vmx-sds
      where: Section 2 (Hazard identification), GHS classification
    - text: The same SDS says dust is flammable and explosive when finely divided and suspended in air, and that dust may form explosive mixtures with air. It says to keep away from heat, sparks, flame and other ignition sources.
      ghs: []
      source: tivar-vmx-sds
      where: Fire-fighting measures and handling text on dust and ignition sources
    - text: The SDS for a pigmented white UHMWPE compound (PolyOne, 2015) classifies it as combustible dusts and as carcinogenicity Category 1A. The SDS says the mixture has not been evaluated as a whole and names no component in the text read. This applies to that formulation, not to unpigmented UHMWPE.
      ghs: []
      source: avient-white-uhmwpe-sds
      where: Section 2 (classification table) and the carcinogenicity section
    - text: The TIVAR VMX SDS says the product contains a component evaluated by IARC as a possible carcinogen (Group 2B). The component is not named in the text read.
      ghs: []
      source: tivar-vmx-sds
      where: Toxicological information, carcinogenicity line
  failure_risks:
    - mode: Loss of stiffness at high temperature
      trigger: Long-term use above 82.2 °C in air (datasheet rating)
      consequence: The heat deflection temperature is 46.7 °C at 1.8 MPa and the melting peak is 135 °C, so the long-term rating leaves a modest margin under a continuous load.
      severity: moderate
      source: tivar-1000-datasheet
      where: Thermal Properties table
    - mode: UV chain scission in a fibre net
      trigger: Sunlight or UV exposure outdoors
      consequence: UV energy breaks polymer chains, and breaking strength falls faster than under salt spray or hygrothermal ageing (study on a fibre barrier net).
      severity: moderate
      source: mdpi-barrier-net
      where: Conclusion (1); Figure 9c
    - mode: Dust explosion
      trigger: Fine dust suspended in air with an ignition source
      consequence: Dust may form explosive mixtures with air (SDS). The hazard applies to dust, not to granular forms of the product.
      severity: high
      source: tivar-vmx-sds
      where: Fire-fighting measures and handling text on dust
    - mode: Brittle fracture at low temperature
      trigger: Temperature below -150 °C
      consequence: The article says UHMWPE fibre becomes brittle below -150 °C.
      severity: low
      source: wiki-uhmwpe
      where: Thermal properties sentence
  side_effects:
    - text: Gel spinning needs about 20 kg of oil for each kilogram of yarn, and removing that oil takes 100 to 200 kg of hexane per kilogram of yarn (Wikipedia).
      affects: Process solvent use and emissions in fibre manufacture
      source: wiki-uhmwpe
      where: Gel spinning section
  handling:
    - text: Avoid dust formation. Ground all transfer, blending and dust-collecting equipment to prevent static sparks, and remove ignition sources from handling and processing areas where dust may be present (SDS, NFPA 484 and NFPA 654 cited).
      source: tivar-vmx-sds
      where: Handling and storage section
    - text: Use local exhaust where dust forms, and minimise inhalation of dust, vapours or mist (SDS, industrial hygiene text).
      source: tivar-vmx-sds
      where: Exposure controls and personal protection section
  mitigations:
    - text: Design to the datasheet long-term limit of 82.2 °C in air for the sheet grade, and to the article's advice of no long periods above 90 °C for the fibre.
      source: tivar-1000-datasheet
      where: Thermal Properties table, Maximum Service Temperature, Air
uses:
  - application: mechanisms
    device: Low-friction, abrasion-resistant industrial parts
    example: The SDS for TIVAR VMX food-grade UHMW-PE gives its recommended use as an industrial application for abrasion and chemical resistant applications and low friction.
    source: tivar-vmx-sds
    where: Section 1 (Identification), recommended use
  - application: structures
    device: UHMWPE fibre barrier net for marine use
    example: A 2022 study tested a UHMWPE fibre barrier net under salt spray, hygrothermal and UV ageing, then built an environmental spectrum to estimate its service life.
    source: mdpi-barrier-net
    where: Title, abstract and results
  - application: radiation-shielding
    device: Polymer shield against galactic cosmic rays (polyethylene, not UHMWPE-specific)
    example: NASA TP-3473 (1994) says that polyethylene reduces heavy-ion fluence more efficiently than PTFE and other polymers, and is more effective for thin shields. The report tests polyethylene, not UHMWPE specifically.
    source: nasa-tp3473
    where: Concluding remarks and the polymer shield discussion (figure 22)
supply:
  - subject: Ethylene and UHMWPE resin and fibre
    abundance: No abundance figure read. The feedstock is ethylene (see recipe).
    producers: []
    critical_lists: []
    recycling: No recycling data for UHMWPE read in a fetched source.
    substitutes: []
    source: wiki-uhmwpe
    where: 'Trade names and manufacturers section (names only, no market shares read): UHMWPE resin from Braskem, Teijin (Endumax), Celanese and Mitsui; GUR resin from Ticona; Dyneema fibre from DSM; Spectra fibre from Honeywell (then AlliedSignal).'
documents:
  - title: Mitsubishi Chemical Advanced Materials TIVAR 1000 UHMW-PE, ASTM product data sheet (Polymershapes copy)
    type: datasheet
    url: https://www.polymershapes.com/wp-content/uploads/2020/09/Material_Data_TIVAR_1000_UHMW-PE.pdf
    year: 2020
  - title: Mitsubishi Chemical Advanced Materials TIVAR VMX food-grade UHMW-PE safety data sheet (Boedeker copy, rev. Feb 2024)
    type: sds
    url: https://www.boedeker.com/Portals/0/Safety%20Data%20Sheets%20SDS/MCAM/MCAM-TIVAR-VMX-FOOD-GRADE-UHMW-EN-SDS-1609-211004-feb-2024.pdf
    year: 2024
  - title: PolyOne (Avient) white UHMWPE safety data sheet, CC10230188 (rev. 12/18/2015)
    type: sds
    url: https://avient.com/sites/default/files/msds/CC10230188-NORTH_AMER-E.pdf
    year: 2015
  - title: Study on the Aging Behavior of an Ultra-High Molecular Weight Polyethylene Fiber Barrier Net in a Marine Environment, Materials 15(16):5599
    type: paper
    url: https://doi.org/10.3390/ma15165599
    year: 2022
  - title: Research on the Anti-Ultraviolet Aging Performance of Fishery HDPE/UHMWPE-Blended Monofilaments (open access, PMC12899940)
    type: paper
    url: https://pmc.ncbi.nlm.nih.gov/articles/PMC12899940/
    year: 2026
  - title: NASA TP-3473, Performance Study of Galactic Cosmic Ray Shield Materials (Kim et al., 1994)
    type: report
    url: https://ntrs.nasa.gov/api/citations/19950010497/downloads/19950010497.pdf
    year: 1994
  - title: NIST Atomic Weights and Isotopic Compositions, carbon and hydrogen stand-alone pages
    type: database
    url: https://physics.nist.gov/cgi-bin/Compositions/stand_alone.pl?ele=C&ascii=html
    year: 2026
gaps:
  - 'No producer market shares or country split for UHMWPE resin or fibre were read in a fetched page; only company names come from Wikipedia. No critical-mineral list check: polyethylene is not a mineral, and no USGS or EU list entry was checked.'
  - Honeywell Spectra S-1000 and Dyneema SK75 datasheets were not read. The Honeywell product pages redirected to an unrelated site, and the Dyneema technical data page returned 404. Fibre tensile strength and modulus in GPa are therefore not entered (the Wikipedia article gives only yield strength).
  - No UV dose and retained-strength number for UHMWPE sheet was read; the 2022 fibre-net study shows UV results only in a figure. PubChem hazard data could not be opened (browser check page); hazards rest on three supplier SDS documents.
  - The 2026 UV paper tests an 80/20 HDPE/UHMWPE blend, not pure UHMWPE. Its values are reported as ratios in the abstract and are not entered as UHMWPE properties.
  - Water absorption for the fibre form, and the moisture or humidity ageing of sheet, were not found in a readable source. The datasheet covers moulded sheet only.
  - Atomic oxygen erosion, outgassing (TML and CVCM), and radiation ageing dose response for UHMWPE were not found in a readable source. The NASA TP-3473 report covers shielding by polyethylene, not ageing.
  - No orbital environment (low-earth-orbit, geo, cislunar) is sourced for UHMWPE, so tags.environments is empty.
  - 'Shore D hardness (about 60 to 65, Wikipedia) and notched Izod impact (above 1,070 J/m, Wikipedia) are not entered: no canonical property name fits them without a custom name, and the Izod result is a non-break value.'
  - 'Property name outside the canonical list: coefficient_of_friction (used as a custom name). Molar mass (2 to 6 million daltons, Wikipedia) is given in the summary and recipe only, not as a property.'
  - Designations (UNS, ASTM D4020 molding grade, ASTM F648 implant grade) were not read in a fetched page, so identity.designations is empty.
  - The NCBI and MDPI pages blocked automated fetch (browser check, HTTP 403). The ageing paper's text was read from its full-text XML (Europe PMC, PMC9413766) instead.
  - The Avient SDS (2015) is for a pigmented white compound. The component behind its carcinogenicity Category 1A is not named in the text read, so it is not assigned to pure UHMWPE.
  - The TIVAR 1000 datasheet is an older ASTM sheet reposted by Polymershapes. Its values may differ from the current Mitsubishi Chemical Advanced Materials sheet, and ISO-based sheets for other TIVAR grades use other test values.
sources:
  wiki-uhmwpe:
    title: Wikipedia, Ultra-high-molecular-weight polyethylene (molar mass, density, mechanical, thermal, production, gel spinning, chemical and oxidation statements)
    url: https://en.wikipedia.org/wiki/Ultra-high-molecular-weight_polyethylene
    kind: web
    license: CC BY-SA (Wikipedia)
    note: 'Secondary source. Values are quoted as stated in the article, with no test standard printed for most of them. Chain length: 100,000 to 250,000 monomer units per UHMWPE molecule, against 700 to 1,800 for HDPE (same article, molecule size sentence).'
  tivar-1000-datasheet:
    title: Mitsubishi Chemical Advanced Materials, TIVAR 1000 UHMW-PE (ASTM product data sheet, Polymershapes copy)
    url: https://www.polymershapes.com/wp-content/uploads/2020/09/Material_Data_TIVAR_1000_UHMW-PE.pdf
    kind: datasheet
    license: Manufacturer data sheet (cited, not reproduced)
    note: Older ASTM-format sheet from Quadrant (now Mitsubishi Chemical Advanced Materials). Read in full with pdftotext.
  tivar-vmx-sds:
    title: Mitsubishi Chemical Advanced Materials, TIVAR VMX food-grade UHMW-PE safety data sheet (Boedeker copy, rev. Feb 2024)
    url: https://www.boedeker.com/Portals/0/Safety%20Data%20Sheets%20SDS/MCAM/MCAM-TIVAR-VMX-FOOD-GRADE-UHMW-EN-SDS-1609-211004-feb-2024.pdf
    kind: datasheet
    license: Safety data sheet (cited, not reproduced)
  avient-white-uhmwpe-sds:
    title: PolyOne (Avient), White UHMWPE safety data sheet, CC10230188 (rev. 12/18/2015)
    url: https://avient.com/sites/default/files/msds/CC10230188-NORTH_AMER-E.pdf
    kind: datasheet
    license: Safety data sheet (cited, not reproduced)
    note: Pigmented compound, not unpigmented UHMWPE.
  mdpi-barrier-net:
    title: Study on the Aging Behavior of an Ultra-High Molecular Weight Polyethylene Fiber Barrier Net in a Marine Environment, Materials 2022, 15(16), 5599
    url: https://doi.org/10.3390/ma15165599
    kind: paper
    license: CC BY (MDPI, open access)
    note: The MDPI page returned HTTP 403; the text was read from its full-text XML on Europe PMC (PMC9413766).
  pmc-blend-uv:
    title: Research on the Anti-Ultraviolet Aging Performance of Fishery HDPE/UHMWPE-Blended Monofilaments (2026)
    url: https://pmc.ncbi.nlm.nih.gov/articles/PMC12899940/
    kind: paper
    license: Open access (PMC)
    note: Read from its full-text XML on Europe PMC. Blend of HDPE with 20 wt% UHMWPE, not pure UHMWPE.
  nasa-tp3473:
    title: NASA Technical Paper 3473, Performance Study of Galactic Cosmic Ray Shield Materials (Kim, Wilson, Thibeault, Nealy, Badavi, Kiefer, November 1994)
    url: https://ntrs.nasa.gov/api/citations/19950010497/downloads/19950010497.pdf
    kind: report
    license: NASA public document
    note: Polyethylene is tested as a shield material, not UHMWPE specifically.
  nist-atomic-weights:
    title: NIST Atomic Weights and Isotopic Compositions for carbon and hydrogen (standard atomic weight intervals)
    url: https://physics.nist.gov/cgi-bin/Compositions/stand_alone.pl?ele=C&ascii=html
    kind: database
    license: Public domain (NIST)
    note: 'Printed intervals: C [12.0096, 12.0116]; H [1.00784, 1.00811] (stand-alone page for H, read in this run). Shares computed from C2H4 (28.05 g/mol): C 85.6 %, H 14.4 %, by Space Mushroom.'
license: CC-BY-4.0
updated: '2026-10-26'
review:
  status: draft
  method: assistant
  checked_values: 24
  unreachable: 4
  caveats: 6
  note: 'Values were read by an AI assistant on 2026-10-26 from the pages named in each entry. Unreachable as readable text: the Honeywell Spectra and Dyneema product pages, PubChem (browser check page), and the MDPI page (HTTP 403, read via Europe PMC instead). Caveats: the TIVAR 1000 values come from an older ASTM sheet; the fibre values come from a secondary article (Wikipedia); the UV evidence is qualitative or from an HDPE/UHMWPE blend; the hazards rest on supplier SDS documents; the polymer shield evidence is for polyethylene in general.'
story:
  recipe:
    line: UHMWPE has the same repeat unit as polyethylene, -CH2-CH2-, formula (C2H4)n (Wikipedia). It is made with very active coordination catalysts (metallocene or Ziegler-Natta) at high ethylene pressure, which gives chains of about 100,000 to 250,000 monomer units, against 700 to 1,800 for HDPE (Wikipedia). Fibre is gel-spun from a solution of about 5 % UHMWPE in an oil.
    parts:
      - name: Ethylene
        symbol: C2H4
        share_note: Single monomer, polymerised to the -CH2-CH2- repeat unit. Molar mass 2 to 6 million daltons.
        role: Only monomer. The grade (sheet or fibre) depends on the catalyst, pressure and processing route, not the chemistry.
      - name: Carbon
        symbol: C
        share_percent: 85.6
        role: Backbone element of the -CH2-CH2- repeat unit.
        share_note: atomic_weight [12.0096, 12.0116] (NIST). Share computed by Space Mushroom from C2H4 (28.05 g/mol).
      - name: Hydrogen
        symbol: H
        share_percent: 14.4
        role: Side groups of the repeat unit.
        share_note: atomic_weight [1.00784, 1.00811] (NIST). Share computed from C2H4.
  risk_groups:
    - title: For people
      level: 0
      verdict: Not classified as hazardous in the pure polymer SDS
      lead: The pure polymer SDS (TIVAR VMX) classifies it as not hazardous, but the powder form is a dust hazard. A pigmented compound is classified differently.
      points:
        - label: The polymer
          line: The food-grade TIVAR VMX SDS gives no GHS classification, signal word or hazard statements.
        - label: Dust
          line: Fine dust suspended in air can form an explosive mixture. The SDS says to avoid dust formation and to ground transfer equipment.
        - label: Pigmented compound
          line: A 2015 SDS for a white UHMWPE compound classifies it for combustible dust and carcinogenicity (Category 1A). The component is not named in the text read.
    - title: If the part fails
      lead: The failure routes in the sources are heat, sunlight and dust.
      points:
        - label: Heat
          line: The sheet grade is rated to 82.2 °C long term in air, with a melting peak at 135 °C and a heat deflection of 46.7 °C at 1.8 MPa.
        - label: Sunlight
          line: In a fibre net, UV breaks polymer chains faster than salt spray or hygrothermal ageing breaks them.
        - label: Cold
          line: The article says the fibre becomes brittle below -150 °C.
  why: UHMWPE is polyethylene with a molar mass of 2 to 6 million daltons. The long chains give it low friction, high impact resistance and high strength when gel-spun. A natural TIVAR 1000 sheet has a tensile strength of 40.0 MPa, an elongation at break of 300 % and a density of 0.930 g/cc. Gel-spun fibre (Dyneema or Spectra) is quoted with a yield strength as high as 2.4 GPa at about 0.97 g/cm3, which is the reason it is used where strength per weight matters.
  uses:
    - where: Industrial wear parts
      line: The SDS for TIVAR VMX gives its recommended use as abrasion and chemical resistant applications with low friction.
    - where: Marine barrier net
      line: A UHMWPE fibre barrier net was tested under salt spray, hygrothermal and UV ageing to build a service-life spectrum (2022).
    - where: Radiation shielding (polyethylene)
      line: NASA TP-3473 finds polyethylene an efficient galactic cosmic ray shield, but it tests polyethylene, not UHMWPE.
  can_do:
    - label: Density
      value: 0.930 g/cc
      benchmark: density
      line: The TIVAR 1000 natural sheet has a density of 0.930 g/cc (ASTM D792). Gel-spun fibre is quoted at 0.97 g/cm3.
    - label: Tensile strength
      value: 40.0 MPa
      benchmark: ultimate_tensile_strength
      line: TIVAR 1000 has a tensile strength of 40.0 MPa and an elongation at break of 300 % (ASTM D638). The datasheet states there is no yield point.
    - label: Heat limit
      value: 82.2 °C
      benchmark: max_service_temp
      line: The long-term service limit in air is 82.2 °C for the TIVAR 1000 sheet grade.
  compare: 'Within this profile, the moulded sheet grade has a tensile strength of 40.0 MPa, while the gel-spun fibre is quoted with a yield strength as high as 2.4 GPa. The ratio of about 60 is only indicative, because the two figures come from different tests (tensile strength on a datasheet, yield strength in a secondary article). The densities are close: 0.930 g/cc for the sheet and 0.97 g/cm3 for the fibre.'
  compare_rows:
    - scope: material
      label: Density
      benchmark: density
    - scope: material
      label: Tensile strength
      benchmark: ultimate_tensile_strength
    - scope: material
      label: Long-term service limit
      benchmark: max_service_temp
  handling:
    - Avoid dust formation, control ignition sources and ground transfer equipment (SDS).
    - Keep long-term service in air at or below 82.2 °C for the sheet grade (datasheet).
    - Note the grade. The TIVAR 1000 values are one natural grade; the fibre values are for an unnamed grade from a secondary source.
  good_for:
    - 'Low-friction wear parts: a dynamic coefficient of friction of 0.12 against steel (TIVAR 1000, dry).'
    - 'Low water uptake: 0.010 % or less after 24 h immersion.'
    - 'High strength per weight in fibre form: a yield strength as high as 2.4 GPa at about 0.97 g/cm3.'
  watch_out:
    - 'Heat: the long-term limit is 82.2 °C in air for the sheet grade, and the article advises no long periods above 90 °C for the fibre.'
    - 'Sunlight: UV ageing cut breaking strength faster than salt spray in a fibre net, and the datasheet rates continuous sunlight as Limited.'
    - 'Dust: the powder form is a combustible dust hazard, and a pigmented compound is classified as a carcinogen (Category 1A) in its SDS.'
    - 'Data gaps: no UV retention value, no orbital erosion or outgassing value and no fibre tensile modulus were found.'
  verdict: UHMWPE is a light, tough, low-friction polymer, and the article says its fibre has a strength-to-weight about 40 % higher than aramid. The sheet grade is limited by heat (82.2 °C long term in air) and by sunlight. The sources do not give a UV or orbital ageing number, so a space application needs its own test data.