Ultra-high-molecular-weight polyethylene UHMWPE

(C2H4)n, ultra-high-molecular-weight polymer of ethylene, 2 to 6 million daltons · CAS 9002-88-4

UHMWPE is polyethylene with a molar mass of about 2 to 6 million daltons.

8 sources · Updated 2026-10-26 · CC BY 4.0

Evidence level

2 of 5

Lab-measured

Density

0.930 g/cc

Tensile strength

40.0 MPa

Heat limit

82.2 °C

Recipe, share of the weight

  • C2H4 Single monomer, polymerised to the -CH2-CH2- repeat unit. Molar mass 2 to 6 million daltons.Ethylene
  • C atomic_weight [12.0096, 12.0116] (NIST). Share computed by Space Mushroom from C2H4 (28.05 g/mol).Carbon
  • H atomic_weight [1.00784, 1.00811] (NIST). Share computed from C2H4.Hydrogen

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

Risk at a glance

  • People None found. Not classified as hazardous in the pure polymer SDS
  • If it fails High. Dust explosion
  • Corrosion Moderate. UV ageing breaks polymer chains and cut a fibre net's breaking strength faster than salt spray or damp heat.

Quick facts: UHMWPE

Key properties of UHMWPE
PropertyValueBasis
Density0.93 to 0.97 g/cm³3 sourced values across conditions
Yield strength19.3 to 2,400 MPa2 sourced values across conditions
Tensile strength40 MPa1 sourced value
Young's modulus0.55 GPa1 sourced value
Thermal conductivity0.41 W/(m·K)1 sourced value
Thermal expansion (CTE)198 ppm/K1 sourced value
Melting point128 to 135 °C2 sourced values across conditions
Maximum service temperature82.2 to 90 °C2 sourced values across conditions

What is the density of Ultra-high-molecular-weight polyethylene (UHMWPE)?

Ultra-high-molecular-weight polyethylene (UHMWPE) has a density of 0.93 to 0.97 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 thermal conductivity of Ultra-high-molecular-weight polyethylene (UHMWPE)?

Ultra-high-molecular-weight polyethylene (UHMWPE) has a thermal conductivity of 0.41 W/(m·K). The source and test conditions are listed in the properties table on this page.

What is the coefficient of thermal expansion of Ultra-high-molecular-weight polyethylene (UHMWPE)?

Ultra-high-molecular-weight polyethylene (UHMWPE) has a coefficient of thermal expansion of 198 ppm/K. The source and test conditions are listed in the properties table on this page.

What is the melting point of Ultra-high-molecular-weight polyethylene (UHMWPE)?

Ultra-high-molecular-weight polyethylene (UHMWPE) has a melting point of 128 to 135 °C. The range covers 2 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 yield strength of Ultra-high-molecular-weight polyethylene (UHMWPE)?

Ultra-high-molecular-weight polyethylene (UHMWPE) has a yield strength of 19.3 to 2,400 MPa. The range covers 2 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 Ultra-high-molecular-weight polyethylene (UHMWPE) used for?

Uses recorded in the sources include Low-friction, abrasion-resistant industrial parts; UHMWPE fibre barrier net for marine use; Polymer shield against galactic cosmic rays (polyethylene, not UHMWPE-specific).

Why it exists

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.

Where it's used

Industrial wear parts

The SDS for TIVAR VMX gives its recommended use as abrasion and chemical resistant applications with low friction.

Marine barrier net

A UHMWPE fibre barrier net was tested under salt spray, hygrothermal and UV ageing to build a service-life spectrum (2022).

Radiation shielding (polyethylene)

NASA TP-3473 finds polyethylene an efficient galactic cosmic ray shield, but it tests polyethylene, not UHMWPE.

Recipe

(C2H4)n, ultra-high-molecular-weight polymer of ethylene, 2 to 6 million daltons

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.

What UHMWPE is made of
IngredientShare of the weightWhat it does
Ethylene C2H4 Single monomer, polymerised to the -CH2-CH2- repeat unit. Molar mass 2 to 6 million daltons. Only monomer. The grade (sheet or fibre) depends on the catalyst, pressure and processing route, not the chemistry.
Carbon C atomic_weight [12.0096, 12.0116] (NIST). Share computed by Space Mushroom from C2H4 (28.05 g/mol). Backbone element of the -CH2-CH2- repeat unit.
Hydrogen H atomic_weight [1.00784, 1.00811] (NIST). Share computed from C2H4. Side groups of the repeat unit.

Weight shares are as printed in the sources.

What it can do

Density

0.930 g/cc

measured

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.

Tensile strength

40.0 MPa

measured

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.

Heat limit

82.2 °C

measured

The long-term service limit in air is 82.2 °C for the TIVAR 1000 sheet grade.

How it compares

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.

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. Other materials are shown beside it; each was measured under its own conditions, so open its page before comparing closely. Compare every grade in the family.

Benchmarks
MeasurementUHMWPECOCEPDMHDPEPMP (TPX)PEPKPPPVC
Thermal behavior and safety
Melting point, TIVAR 1000 (crystalline peak)ASTM D3418, as printed on the datasheet135 °Cno datano data130 to 135 °C232 °C128 °C> 220 °C140 °Cno data
Melting point onset, gel-spun UHMWPE fibre127.7 °C5no datano data130 to 135 °C232 °C128 °C> 220 °C140 °Cno data
Heat deflection temperature, TIVAR 1000 at 1.8 MPaASTM D648, as printed on the datasheet46.7 °C127 °Cno data165 to 176 °F127 °Cno datano data97 °C69.4 °C
Thermal conductivity, TIVAR 1000 natural UHMW-PE sheetAs printed on the datasheet0.409 W/m-Kno datano datano datano datano datano datano datano data
Physical and electrical
Density, TIVAR 1000 natural UHMW-PE sheetASTM D792, as printed on the datasheet0.93 g/cc1020 kg/m31.19 g/cm³0.959 g/cm³833 kg/m30.959 g/cm³0.948 g/cm³0.9 g/cm³1.32 g/cc
Density, UHMWPE in general (typical range)Stated in a Wikipedia article (secondary source)0.93 g/cm³1020 kg/m31.19 g/cm³0.959 g/cm³833 kg/m30.959 g/cm³0.948 g/cm³0.9 g/cm³1.32 g/cc
Density, gel-spun UHMWPE fibre (Dyneema SK75)> 0.97 g/cm³11020 kg/m31.19 g/cm³0.959 g/cm³833 kg/m30.959 g/cm³0.948 g/cm³0.9 g/cm³1.32 g/cc
Other measurements
Tensile strength, TIVAR 1000 natural UHMW-PE sheetASTM D638, as printed on the datasheet40 MPa246 MPa10.5 MPano data25 MPa21 MPa19 MPano data33 MPa
Tensile yield strength, UHMWPE (typical values)Stated in a Wikipedia article (secondary source)19.3 MPa3no datano data290 kg/cm²30 MPa290 kg/cm²no datano data44.8 MPa
Yield strength, gel-spun UHMWPE fibre (as high as)< 2.4 GPa4no datano data290 kg/cm²30 MPa290 kg/cm²no datano data44.8 MPa
Elongation at break, TIVAR 1000 natural UHMW-PE sheetASTM D638, as printed on the datasheet300 %120 %255 %> 400 %22 %400 %25 %no data140 %
Elongation at break, UHMWPE (typical range)Stated in a Wikipedia article (secondary source)250 %120 %255 %> 400 %22 %400 %25 %no data140 %
Tensile modulus, TIVAR 1000 natural UHMW-PE sheetASTM D638, as printed on the datasheet0.552 GPa3200 MPano data750 MPa1900 MPa13000 kg/cm²no datano data2.3 GPa
Flexural strength, TIVAR 1000 natural UHMW-PE sheetASTM D790, as printed on the datasheet24.1 MPano datano datano data36 MPano datano datano data88.5 MPa
Flexural modulus, TIVAR 1000 natural UHMW-PE sheetASTM D790, as printed on the datasheet0.6 GPano datano data13000 kg/cm²1450 MPano data24 MPa1480 MPa2.65 GPa
Dynamic coefficient of friction, TIVAR 1000 against steelQTM55007, as printed on the datasheet0.12 -no datano datano datano datano datano datano datano data
Maximum service temperature in air, TIVAR 1000 (long term)Datasheet rating, as printed82.2 °C6no data150 °C180 °Fno datano datano datano data< 60 °C
Long-term service limit, UHMWPE fibre (article advice)Stated in a Wikipedia article (secondary source)< 90 °Cno data150 °C180 °Fno datano datano datano data< 60 °C
Linear coefficient of thermal expansion, TIVAR 1000ASTM E831, as printed on the datasheet198 µm/m-°Cno data8.9×10^-5 in/in/°Fno data1.17×10^-4 cm/cm°Cno datano datano data54 µm/m-°C
Water absorption, TIVAR 1000 (24 h immersion)ASTM D570, as printed on the datasheet< 0.01 %7no datano data< 0.1 %no datano datano datano datano data
Dielectric constant, TIVAR 1000ASTM D150, as printed on the datasheet2.3 -no datano datano data2.11 -no datano datano data3.58 -
Dielectric strength, TIVAR 1000 (short term)ASTM D149, as printed on the datasheet90.6 kV/mmno datano datano data32 kV/mmno datano datano datano data
Dissipation factor, TIVAR 1000ASTM D150, as printed on the datasheet5×10^-4 -no datano datano datano datano datano datano datano data
Flash point, food-grade TIVAR VMX UHMW-PE (SDS)As printed on the SDS (printed as >662°F)> 662 °Fno datano datano datano datano data> 93 °Cno datano data

Why choose it, and why not

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 for

  • 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.

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.

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.

Notes for the numbered rows
#MeasurementMethodConditionsCaveat
1Density, gel-spun UHMWPE fibre (Dyneema SK75)Stated in a Wikipedia article (secondary source); the article says "as low as"form gel-spun fibre, grade named in the article as Dyneema SK75temperature not stated—
2Tensile strength, TIVAR 1000 natural UHMW-PE sheet—grade TIVAR 1000, naturaltemperature not statednote The datasheet says the material has no yield point, so this is the tensile strength.—
3Tensile yield strength, UHMWPE (typical values)—form moulded or extruded UHMWPE, typical valuestest not statedThe TIVAR 1000 datasheet gives no yield point for its grade; this range comes from the article only.
4Yield strength, gel-spun UHMWPE fibre (as high as)Stated in a Wikipedia article (secondary source); the article says "as high as"form gel-spun fibre (grade not named in the article)basis the article reports yield strength, not tensile strength—
5Melting point onset, gel-spun UHMWPE fibreStated in a Wikipedia article (secondary source); test method not printedform fibre (grade not named in the article)basis melting point onset, as stated—
6Maximum service temperature in air, TIVAR 1000 (long term)—environment airduration long termgrade TIVAR 1000, natural—
7Water absorption, TIVAR 1000 (24 h immersion)—immersion 24 hbasis printed as <= 0.010 %grade TIVAR 1000, natural—

Corrosion and compatibility

What happens when it meets other materials and environments.

Corrosion and compatibility
EnvironmentConcernWhat happens
Ultraviolet light and sunlight moderate UV ageing breaks polymer chains and cut a fibre net's breaking strength faster than salt spray or damp heat.1
UV ageing of a UHMWPE/HDPE blend (80/20) moderate 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.2
Salt spray and hot humid (hygrothermal) ageing of a fibre net moderate Salt spray lowered breaking strength to 655 N after 60 days; hygrothermal ageing took it from 850 N to 703 N in 10 days.3
Long-term heat in air moderate The sheet grade is rated to 82.2 °C long term in air and deflects at 46.7 °C under 1.8 MPa.4
Oxidation and radiation processing low Radiation cross-linking and heat treatment are used to improve oxidation resistance; vitamin E is also used.5
Water and humidity low Water absorption is 0.010 % or less after 24 h immersion.6
Chemicals (acids, alkalis, solvents, hydrocarbons) moderate Aromatic hydrocarbons are unacceptable; strong acids and ketones or esters are limited; most other chemicals are acceptable.7
Corrosion details
#EnvironmentDetailsTest conditions
1 Ultraviolet light and sunlight 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. basis qualitative statement and figure; UV irradiance, lamp type and exposure time are not stated in the text readspecimen UHMWPE fibre barrier net, not moulded sheet
2 UV ageing of a UHMWPE/HDPE blend (80/20) 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. basis 80/20 wt% HDPE/UHMWPE blend, UVA-340 lamp, ISO 4892-3 and ASTM G154, 0 to 600 h
3 Salt spray and hot humid (hygrothermal) ageing of a fibre net 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. 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
4 Long-term heat in air 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. basis datasheet rating and standard test; no ageing time or oxygen level printed
5 Oxidation and radiation processing 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. basis qualitative statements and processing doses; no ageing test
6 Water and humidity 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. basis 24 h immersion, ASTM D570, datasheet value
7 Chemicals (acids, alkalis, solvents, hydrocarbons) 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. basis qualitative ratings; no concentration, temperature or time printed

Risks and side effects

Hazards to people, what happens when a cell overheats, and how the material is handled and stored.

For people

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.

The polymer
The food-grade TIVAR VMX SDS gives no GHS classification, signal word or hazard statements.
Dust
Fine dust suspended in air can form an explosive mixture. The SDS says to avoid dust formation and to ground transfer equipment.
Pigmented compound
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.

If the part fails

The failure routes in the sources are heat, sunlight and dust.

Heat
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.
Sunlight
In a fibre net, UV breaks polymer chains faster than salt spray or hygrothermal ageing breaks them.
Cold
The article says the fibre becomes brittle below -150 °C.

Test details
The original wording and numbers from the sources, for readers who want them.

Failure risks

Failure risks
FailureTrigger and consequence
Loss of stiffness at high temperaturemoderate severityLong-term use above 82.2 °C in air (datasheet rating)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.
UV chain scission in a fibre netmoderate severitySunlight or UV exposure outdoorsUV energy breaks polymer chains, and breaking strength falls faster than under salt spray or hygrothermal ageing (study on a fibre barrier net).
Dust explosionhigh severityFine dust suspended in air with an ignition sourceDust may form explosive mixtures with air (SDS). The hazard applies to dust, not to granular forms of the product.
Brittle fracture at low temperaturelow severityTemperature below -150 °CThe article says UHMWPE fibre becomes brittle below -150 °C.

Side effects on surrounding parts

Side effects on surrounding parts
AffectsEffect
Process solvent use and emissions in fibre manufactureGel 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).

Handling and storage

  • 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).
  • Use local exhaust where dust forms, and minimise inhalation of dust, vapours or mist (SDS, industrial hygiene text).

Mitigations

  • 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.

Supply and geography

How common the raw materials are and where they come from.

Ethylene and UHMWPE resin and fibre

No abundance figure read. The feedstock is ethylene (see recipe).

Recycling
No recycling data for UHMWPE read in a fetched source.