Polyethylene PE
(C2H4)n, polymer of ethylene · CAS 9002-88-4
Polyethylene is the ethylene polymer used as the shutdown layer of lithium-ion battery separators and as a general engineering plastic.
Evidence level
2 of 5
Lab-measured
- 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.
Density
0.959 g/cm3
Yield strength
17 MPa
Shutdown
130 °C
Recipe, share of the weight
- C2H4 Single monomer, polymerised to the -CH2-CH2- repeat unit; atoms C2H4Ethylene
- C atomic_weight [12.0096, 12.0116]Carbon
- H atomic_weight [1.00784, 1.00811]Hydrogen
Best for
Low-density, tough, chemically resistant plastic, and a melt-based shutdown near 130 °C in a battery separator
Weakest at
Stiffness and heat resistance: a separator layer melts near 130 to 135 °C, and the H5818J HDPE grade has a flexural modulus of 13000 kg/cm2
Risk at a glance
- People Low. No hazard statements printed
- If it fails Moderate. Shutdown of the separator at its polyethylene melting point
- Corrosion Moderate. Semi-crystalline polyethylene can fail by brittle cracking under stress in stress-cracking agents; molar mass and tie molecules control resistance.
Quick facts: PE
| Property | Value | Basis |
|---|---|---|
| Density | 0.93 to 0.96 g/cm³ | 3 sourced values across conditions |
| Yield strength | 17 to 28.4 MPa | 2 sourced values across conditions |
| Tensile strength | 21 to 30 MPa | 2 sourced values across conditions |
| Young's modulus | 0.8 to 1.27 GPa | 2 sourced values across conditions |
| Melting point | 128 to 135 °C | 2 sourced values across conditions |
What is the density of Polyethylene (PE)?
Polyethylene (PE) has a density of 0.93 to 0.96 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 melting point of Polyethylene (PE)?
Polyethylene (PE) 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 Polyethylene (PE)?
Polyethylene (PE) has a yield strength of 17 to 28.4 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 the tensile strength of Polyethylene (PE)?
Polyethylene (PE) has a tensile strength of 21 to 30 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 the Young's modulus of Polyethylene (PE)?
Polyethylene (PE) has a Young's modulus of 0.8 to 1.27 GPa. 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 Polyethylene (PE) used for?
Uses recorded in the sources include Microporous separator between the electrodes of a lithium-ion cell; Injection-molded plastic parts.
Why it exists
Polyethylene is an ethylene polymer used in two very different ways. In a lithium-ion cell, a thin microporous polyethylene separator shuts down near 130 °C by closing its pores, which the patent describes as its purpose. In engineering, polyethylene is an injection-molded plastic: a general-purpose HDPE grade H5818J has a density of 0.959 g/cm3 and a tensile strength at yield of 290 kg/cm2, and a PE-UHMW grade (Braskem Utec 3041) has a density of 925 kg/m3, a yield strength of 17 MPa and an elongation at break of 400 %.
Where it's used
Battery separator
A polyethylene microporous separator sits between the electrodes of a lithium-ion cell. A PP/PE/PP tri-layer uses the PE layer as the shutdown layer, which melts at 135 °C per an industry article.
Injection-molded parts
H5818J is a general-purpose HDPE resin for injection molding. The recycled Recythen grade is listed at 950 kg/m3.
Recipe
(C2H4)n, polymer of ethylene
Polyethylene repeat unit -CH2-CH2-, formula (C2H4)n (Wikipedia, Polyethylene). HDPE is defined as density 0.941 g/cm3 or more and is made with chromium/silica (Phillips), Ziegler-Natta or metallocene catalysts. LDPE is 0.910 to 0.940 g/cm3 and is made by free-radical polymerisation. UHMWPE has a molar mass of about 2 to 6 million daltons (Wikipedia, UHMWPE), made by coordination polymerisation with very active catalysts at high ethylene pressure.
| Ingredient | Share of the weight | What it does |
|---|---|---|
| Ethylene C2H4 | Single monomer, polymerised to the -CH2-CH2- repeat unit; atoms C2H4 | Only monomer for all three grades; grade differences come from catalyst, pressure and molar mass. |
| Carbon C | atomic_weight [12.0096, 12.0116] | Standard atomic weight interval, NIST. Share computed from C2H4 (28.05 g/mol) with the NIST carbon value. |
| Hydrogen H | atomic_weight [1.00784, 1.00811] | Standard atomic weight interval, NIST. Share computed from C2H4. |
Weight shares are as printed in the sources.
What it can do
Density
0.959 g/cm3
measured
The virgin HDPE grade H5818J has a density of 0.959 g/cm3 (ASTM D 1505). The PE-UHMW grade Utec 3041 gives 925 kg/m3 (ASTM D 792).
Yield strength
17 MPa
measured
The Braskem Utec 3041 page gives a tensile strength at yield of 17 MPa (ISO 527), with an elongation at break of 400 %.
Shutdown
130 °C
measured
A polyethylene microporous separator is described as shutting down at about 130 °C, with the shutdown to occur below 130 °C in the detailed description.
How it compares
Within this profile, the UHMW-PE grade is 925 kg/m3 and the virgin HDPE grade is 0.959 g/cm3, so the UHMW grade is the lighter of the two. The stiffness is not comparable across the two sources: H5818J gives a flexural modulus of 13000 kg/cm2, and the Recythen grade a tensile modulus of 800 MPa.
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.
| Measurement | PE | COC | EPDM | HDPE | PMP (TPX) | PK | PP | PVC | UHMWPE |
|---|---|---|---|---|---|---|---|---|---|
| Thermal behavior and safety | |||||||||
| Melting temperature, HDPE pipe grade (ASTM D3418)Value printed in a supplier data table | 128 °C5 | no data | no data | 130 to 135 °C | 232 °C | > 220 °C | 140 °C | no data | 135 °C |
| Thermal shutdown temperature of a polyethylene microporous battery separator (approximate) | < 130 °C10 | no data | no data | 130 to 135 °C | 232 °C | > 220 °C | 140 °C | no data | 135 °C |
| Melting point of the PE layer of a PP/PE/PP separator | 135 °C11 | no data | no data | 130 to 135 °C | 232 °C | > 220 °C | 140 °C | no data | 135 °C |
| Physical and electrical | |||||||||
| Density, general-purpose HDPE injection grade H5818J | 0.959 g/cm³1 | 1020 kg/m3 | 1.19 g/cm³ | 0.959 g/cm³ | 833 kg/m3 | 0.948 g/cm³ | 0.9 g/cm³ | 1.32 g/cc | 0.93 g/cc |
| Density, recycled-content HDPE (Recythen)ISO 1183, as printed in a supplier data sheet | 950 kg/m3 | 1020 kg/m3 | 1.19 g/cm³ | 0.959 g/cm³ | 833 kg/m3 | 0.948 g/cm³ | 0.9 g/cm³ | 1.32 g/cc | 0.93 g/cc |
| Density, PE-UHMW grade Utec 3041 | 925 kg/m36 | 1020 kg/m3 | 1.19 g/cm³ | 0.959 g/cm³ | 833 kg/m3 | 0.948 g/cm³ | 0.9 g/cm³ | 1.32 g/cc | 0.93 g/cc |
| Other measurements | |||||||||
| Tensile strength at yield, HDPE injection grade H5818J | 290 kg/cm²2 | no data | no data | 290 kg/cm² | 30 MPa | no data | no data | 44.8 MPa | 19.3 MPa |
| Flexural modulus, HDPE injection grade H5818J (flexural, not tensile) | 13000 kg/cm²3 | 3200 MPa | no data | 750 MPa | 1900 MPa | no data | no data | 2.3 GPa | 0.552 GPa |
| Tensile strength, recycled HDPE (Recythen), ISO 527ISO 527, as printed in a supplier data sheet | 21 MPa4 | 46 MPa | 10.5 MPa | no data | 25 MPa | 19 MPa | no data | 33 MPa | 40 MPa |
| Tensile modulus, recycled HDPE (Recythen), ISO 527ISO 527, as printed in a supplier data sheet | 800 MPa | 3200 MPa | no data | 750 MPa | 1900 MPa | no data | no data | 2.3 GPa | 0.552 GPa |
| Tensile strength at yield, PE-UHMW grade Utec 3041 | 17 MPa7 | no data | no data | 290 kg/cm² | 30 MPa | no data | no data | 44.8 MPa | 19.3 MPa |
| Tensile strength at break, PE-UHMW grade Utec 3041 | 30 MPa8 | 46 MPa | 10.5 MPa | no data | 25 MPa | 19 MPa | no data | 33 MPa | 40 MPa |
| Elongation at break, PE-UHMW grade Utec 3041 | 400 %9 | 120 % | 255 % | > 400 % | 22 % | 25 % | no data | 140 % | 300 % |
Why choose it, and why not
Good for
- Light plastic parts: 0.959 g/cm3 for the virgin HDPE injection grade, and 925 kg/m3 for the PE-UHMW grade.
- Tough, stretchy parts: the PE-UHMW grade elongates by 400 % before breaking.
- Battery separator shutdown: a polyethylene layer closes the pores near 130 °C.
Watch out for
- Heat: a polyethylene separator layer melts near 130 to 135 °C, and the Utec 3041 page gives no service temperature.
- Stiffness: the flexural modulus of H5818J is 13000 kg/cm2, and no modulus was taken for the PE-UHMW grade.
- Data gaps: no erosion yield in orbit, or outgassing value was found for this profile.
Polyethylene is a light, tough plastic in its HDPE and UHMW forms, and the shutdown layer of many lithium-ion separators at about 130 °C. The sourced values are one virgin HDPE grade, a recycled HDPE, one PE-UHMW grade, and two separator statements. The orbital erosion and outgassing values are not in this profile.
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, general-purpose HDPE injection grade H5818J | ASTM D 1505, as printed in a manufacturer product page | grade H5818J (HDPE, general purpose, injection molding)temperature not stated | — |
| 2 | Tensile strength at yield, HDPE injection grade H5818J | ASTM D 638, as printed in a manufacturer product page | grade H5818J (HDPE, injection molding)test speed crosshead 50 mm/minunit in source kg/cm2 | The page gives the value in kg/cm2 and does not convert it; 290 kg/cm2 is about 28 MPa. |
| 3 | Flexural modulus, HDPE injection grade H5818J (flexural, not tensile) | ASTM D 790, as printed in a manufacturer product page | grade H5818J (HDPE, injection molding)temperature not stated | — |
| 4 | Tensile strength, recycled HDPE (Recythen), ISO 527 | — | grade Recythen HDPEtest condition none listed on the pagenote in source page does not say whether this is yield or break | — |
| 5 | Melting temperature, HDPE pipe grade (ASTM D3418) | — | grade HDPE pipe grade table (grade name not printed in the extracted table)test ASTM D3418 as printed | The table was flattened during extraction, so the mapping of values to grades is taken from the table headings; check the original page before relying on it. |
| 6 | Density, PE-UHMW grade Utec 3041 | ASTM D 792, as printed in a manufacturer data sheet (via Material Data Center) | grade Utec 3041 (PE-UHMW, Braskem)temperature not stated | — |
| 7 | Tensile strength at yield, PE-UHMW grade Utec 3041 | ISO 527, as printed in a manufacturer data sheet (via Material Data Center) | grade Utec 3041 (PE-UHMW, Braskem)test ISO 527temperature not stated | — |
| 8 | Tensile strength at break, PE-UHMW grade Utec 3041 | ISO 527, as printed in a manufacturer data sheet (via Material Data Center) | grade Utec 3041 (PE-UHMW, Braskem)test ISO 527temperature not stated | — |
| 9 | Elongation at break, PE-UHMW grade Utec 3041 | ISO 527, as printed in a manufacturer data sheet (via Material Data Center) | grade Utec 3041 (PE-UHMW, Braskem)test ISO 527temperature not stated | — |
| 10 | Thermal shutdown temperature of a polyethylene microporous battery separator (approximate) | Value stated in the background and detailed description of a patent | membrane polyethylene microporous separator for lithium-ion cellsbasis approximate; the patent says the shutdown should occur at a temperature of less than 130 °C | — |
| 11 | Melting point of the PE layer of a PP/PE/PP separator | Value stated in an industry article; no measurement described | layer PE layer of a tri-layer PP/PE/PP separatornote in source PP layer given as 165 °C in the same article | — |
Corrosion and compatibility
What happens when it meets other materials and environments.
| Environment | Concern | What happens |
|---|---|---|
| Ultraviolet light | not rated | UHMWPE is described as very resistant to UV radiation; ordinary polyethylene yellows as it ages.1 |
| Oxidation (gentle oxidants and reducing agents) | low | Most LDPE, MDPE and HDPE grades resist gentle oxidants; oxidation-stabilised UHMWPE is more resistant.2 |
| Environmental stress cracking (ESC) in stress-cracking agents | moderate | Semi-crystalline polyethylene can fail by brittle cracking under stress in stress-cracking agents; molar mass and tie molecules control resistance.3 |
| Strong acids, strong bases and most chemicals | low | Polyethylene grades resist strong acids and bases; UHMWPE resists most chemicals except some oxidising acids.4 |
| # | Environment | Details | Test conditions |
|---|---|---|---|
| 1 | Ultraviolet light | Wikipedia's UHMWPE article says the material is very resistant to water, moisture, most chemicals, UV radiation and micro-organisms. The Polyethylene article says polyethylene yellows as it ages, without a mechanism or a dose. No UV exposure time or retained property was read in a fetched page. | basis qualitative statements only |
| 2 | Oxidation (gentle oxidants and reducing agents) | Wikipedia says most LDPE, MDPE and HDPE grades are resistant to gentle oxidants and reducing agents. For UHMWPE it says vitamin E stabilisation gives improved oxidation resistance without thermal treatment, and that the Hylamer variant showed susceptibility to oxidation. | basis qualitative statements; no test standard or time printed |
| 3 | Environmental stress cracking (ESC) in stress-cracking agents | Wikipedia says semi-crystalline polymers such as polyethylene show brittle fracture under stress in stress-cracking agents. The early LDPE ESC problem was solved by raising molecular weight, and ESC resistance is controlled by the number of tie molecules and the strength of the crystals that anchor them. Named tests include the Bell Telephone test, the Bergen jig, an Igepal detergent test, and a test said to match ASTM D1693 on a shorter time scale. The article says LLDPE films can have better ESC resistance than LDPE. | basis qualitative; no stress level, agent or time printed |
| 4 | Strong acids, strong bases and most chemicals | Wikipedia says most LDPE, MDPE and HDPE grades have excellent chemical resistance and are not attacked by strong acids or strong bases. For UHMWPE it says resistance to acids, alkalis and many corrosive chemicals, except some oxidising acids. No concentration or temperature is printed. | basis qualitative statements |
Risks and side effects
Hazards to people, what happens when a cell overheats, and how the material is handled and stored.
For people
The sources read here do not describe health effects of polyethylene. The one SDS page read (ChemicalBook, CAS 9002-88-4) prints no signal word and no hazard statements.
- Handling
- The Recythen data sheet asks for pre-drying at 80 °C for 2 to 3 h before molding, and a processing humidity of 0.15 % or less.
If it fails
The failure route in the sources is thermal, inside a battery.
- Separator shutdown
- A patent describes shutdown of a polyethylene separator around 130 °C, and an article gives the PE layer a melting point of 135 °C.
Handling and storage
- Service limits
- The PE-UHMW grade Utec 3041 is listed with a yield strength of 17 MPa and an elongation at break of 400 %, both by ISO 527.
Test details
The original wording and numbers from the sources, for readers who want them.
Failure risks
| Failure | Trigger and consequence |
|---|---|
| Shutdown of the separator at its polyethylene melting pointmoderate severity | Cell temperature reaching about 130 °CThe PE layer closes the pores and stops ion flow. The patent describes this as the intended shutdown. The article says the higher-melting PP layer of a tri-layer separator stays solid. |
Handling and storage
- Dry the pellets before processing: the Recythen data sheet gives a pre-drying temperature of 80 °C for 2 to 3 h, and a processing humidity of 0.15 % or less, for injection molding and extrusion.
Supply and geography
How common the raw materials are and where they come from.
Polyethylene
not searched
- Recycling
- The Recythen data sheet names a recycled-content HDPE grade, but gives no recycled percentage.
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: polyethylene
spore_version: 0.2
family: polyolefins
name: Polyethylene
abbreviation: PE
role: lithium-ion separator polymer and general engineering thermoplastic
category: polymers
type: polyolefins
summary: |
Polyethylene is the ethylene polymer used as the shutdown layer of lithium-ion battery separators and as a general engineering plastic. A general-purpose virgin HDPE injection grade (H5818J) has a density of 0.959 g/cm3 and a tensile strength at yield of 290 kg/cm2. A PE-UHMW grade (Braskem Utec 3041) lists a density of 925 kg/m3, a tensile strength at yield of 17 MPa and an elongation at break of 400 %. A polyethylene microporous separator is stated to shut down, closing its pores, around 130 °C.
best_for: Low-density, tough, chemically resistant plastic, and a melt-based shutdown near 130 °C in a battery separator
weakest_at: 'Stiffness and heat resistance: a separator layer melts near 130 to 135 °C, and the H5818J HDPE grade has a flexural modulus of 13000 kg/cm2'
identity:
formula: (C2H4)n, polymer of ethylene
cas: 9002-88-4
source: scg-h5818j
where: Product page for grade H5818J, which describes it as a high density polyethylene resin (HDPE). CAS number 9002-88-4 is printed in Sections 1 and 3 of the SDS listed as chemicalbook-pe-sds.
tags:
environments:
- low-earth-orbit
stresses:
- thermal-cycling
- extreme-heat
applications:
- batteries
- structures
- thermal-control
properties:
- benchmark: density
label: Density, general-purpose HDPE injection grade H5818J
value: 0.959
unit: g/cm3
scope: material
conditions:
grade: H5818J (HDPE, general purpose, injection molding)
temperature: not stated
method: ASTM D 1505, as printed in a manufacturer product page
status: ground
source: scg-h5818j
where: Physical table, row Density
- benchmark: yield_strength
label: Tensile strength at yield, HDPE injection grade H5818J
value: 290
unit: kg/cm2
scope: material
conditions:
grade: H5818J (HDPE, injection molding)
test_speed: crosshead 50 mm/min
unit_in_source: kg/cm2
method: ASTM D 638, as printed in a manufacturer product page
status: ground
note: The page gives the value in kg/cm2 and does not convert it; 290 kg/cm2 is about 28 MPa.
source: scg-h5818j
where: Mechanical table, row Tensile Strength at Yield
- benchmark: elastic_modulus
label: Flexural modulus, HDPE injection grade H5818J (flexural, not tensile)
value: 13000
unit: kg/cm2
scope: material
conditions:
grade: H5818J (HDPE, injection molding)
temperature: not stated
method: ASTM D 790, as printed in a manufacturer product page
status: ground
source: scg-h5818j
where: Mechanical table, row Flexural Modulus
- benchmark: density
label: Density, recycled-content HDPE (Recythen)
value: 950
unit: kg/m3
scope: material
conditions:
grade: Recythen HDPE (product name suggests recycled resin; the page does not state the recycled content)
temperature: not stated
method: ISO 1183, as printed in a supplier data sheet
status: ground
source: recythen-hdpe
where: Other properties table, row Density
- benchmark: ultimate_tensile_strength
label: Tensile strength, recycled HDPE (Recythen), ISO 527
value: 21
unit: MPa
scope: material
conditions:
grade: Recythen HDPE
test_condition: none listed on the page
note_in_source: page does not say whether this is yield or break
method: ISO 527, as printed in a supplier data sheet
status: ground
source: recythen-hdpe
where: Mechanical properties table, row Tensile Strength
- benchmark: elastic_modulus
label: Tensile modulus, recycled HDPE (Recythen), ISO 527
value: 800
unit: MPa
scope: material
conditions:
grade: Recythen HDPE
test_condition: none listed on the page
method: ISO 527, as printed in a supplier data sheet
status: ground
source: recythen-hdpe
where: Mechanical properties table, row Tensile Modulus
- benchmark: melting_point
label: Melting temperature, HDPE pipe grade (ASTM D3418)
value: 128
unit: °C
scope: material
conditions:
grade: HDPE pipe grade table (grade name not printed in the extracted table)
test: ASTM D3418 as printed
method: Value printed in a supplier data table
status: ground
note: The table was flattened during extraction, so the mapping of values to grades is taken from the table headings; check the original page before relying on it.
source: pertachem-hdpe
where: HDPE PIPE grade table, row Melting Temperature. The table's other pipe-grade values look inconsistent, so only this melting temperature is kept.
- benchmark: density
label: Density, PE-UHMW grade Utec 3041
value: 925
unit: kg/m3
scope: material
conditions:
grade: Utec 3041 (PE-UHMW, Braskem)
temperature: not stated
method: ASTM D 792, as printed in a manufacturer data sheet (via Material Data Center)
status: ground
source: utec-3041
where: Other properties table, row Density
- benchmark: yield_strength
label: Tensile strength at yield, PE-UHMW grade Utec 3041
value: 17
unit: MPa
scope: material
conditions:
grade: Utec 3041 (PE-UHMW, Braskem)
test: ISO 527
temperature: not stated
method: ISO 527, as printed in a manufacturer data sheet (via Material Data Center)
status: ground
source: utec-3041
where: Mechanical properties, ISO Data, row Yield stress
- benchmark: ultimate_tensile_strength
label: Tensile strength at break, PE-UHMW grade Utec 3041
value: 30
unit: MPa
scope: material
conditions:
grade: Utec 3041 (PE-UHMW, Braskem)
test: ISO 527
temperature: not stated
method: ISO 527, as printed in a manufacturer data sheet (via Material Data Center)
status: ground
source: utec-3041
where: Mechanical properties, ISO Data, row Stress at break
- benchmark: elongation
label: Elongation at break, PE-UHMW grade Utec 3041
value: 400
unit: '%'
scope: material
conditions:
grade: Utec 3041 (PE-UHMW, Braskem)
test: ISO 527
temperature: not stated
method: ISO 527, as printed in a manufacturer data sheet (via Material Data Center)
status: ground
source: utec-3041
where: Mechanical properties, ISO Data, row Strain at break
- benchmark: melting_point
label: Thermal shutdown temperature of a polyethylene microporous battery separator (approximate)
value: 130
bound: upper
unit: °C
scope: material
conditions:
membrane: polyethylene microporous separator for lithium-ion cells
basis: approximate; the patent says the shutdown should occur at a temperature of less than 130 °C
method: Value stated in the background and detailed description of a patent
status: ground
source: patent-us6749961
where: Background of the Invention (around 130 °C); Detailed Description (less than 130 °C)
- benchmark: melting_point
label: Melting point of the PE layer of a PP/PE/PP separator
value: 135
unit: °C
scope: material
conditions:
layer: PE layer of a tri-layer PP/PE/PP separator
note_in_source: PP layer given as 165 °C in the same article
method: Value stated in an industry article; no measurement described
status: ground
source: volta-separators
where: Section on tri-layer separators and the abuse-event paragraph
corrosion:
- environment: Ultraviolet light
headline: UHMWPE is described as very resistant to UV radiation; ordinary polyethylene yellows as it ages.
effect: Wikipedia's UHMWPE article says the material is very resistant to water, moisture, most chemicals, UV radiation and micro-organisms. The Polyethylene article says polyethylene yellows as it ages, without a mechanism or a dose. No UV exposure time or retained property was read in a fetched page.
rating: unknown
conditions:
basis: qualitative statements only
source: wiki-uhmwpe
where: Properties section; Polyethylene article, ageing sentence
- environment: Oxidation (gentle oxidants and reducing agents)
headline: Most LDPE, MDPE and HDPE grades resist gentle oxidants; oxidation-stabilised UHMWPE is more resistant.
effect: Wikipedia says most LDPE, MDPE and HDPE grades are resistant to gentle oxidants and reducing agents. For UHMWPE it says vitamin E stabilisation gives improved oxidation resistance without thermal treatment, and that the Hylamer variant showed susceptibility to oxidation.
rating: low
conditions:
basis: qualitative statements; no test standard or time printed
source: wiki-polyethylene
where: Chemical resistance section
- environment: Environmental stress cracking (ESC) in stress-cracking agents
headline: Semi-crystalline polyethylene can fail by brittle cracking under stress in stress-cracking agents; molar mass and tie molecules control resistance.
effect: Wikipedia says semi-crystalline polymers such as polyethylene show brittle fracture under stress in stress-cracking agents. The early LDPE ESC problem was solved by raising molecular weight, and ESC resistance is controlled by the number of tie molecules and the strength of the crystals that anchor them. Named tests include the Bell Telephone test, the Bergen jig, an Igepal detergent test, and a test said to match ASTM D1693 on a shorter time scale. The article says LLDPE films can have better ESC resistance than LDPE.
rating: moderate
conditions:
basis: qualitative; no stress level, agent or time printed
source: wiki-esc
where: Polyethylene section; Named tests section
- environment: Strong acids, strong bases and most chemicals
headline: Polyethylene grades resist strong acids and bases; UHMWPE resists most chemicals except some oxidising acids.
effect: Wikipedia says most LDPE, MDPE and HDPE grades have excellent chemical resistance and are not attacked by strong acids or strong bases. For UHMWPE it says resistance to acids, alkalis and many corrosive chemicals, except some oxidising acids. No concentration or temperature is printed.
rating: low
conditions:
basis: qualitative statements
source: wiki-uhmwpe
where: Properties section (chemical resistance)
risks:
hazards:
- text: The ChemicalBook polyethylene SDS prints no signal word and no hazard statements in Section 2 (Hazards identification). Section 9 gives a flash point of 270 °C and lists auto-ignition temperature as no data available.
ghs: []
source: chemicalbook-pe-sds
where: Sections 2 and 9
failure_risks:
- mode: Shutdown of the separator at its polyethylene melting point
trigger: Cell temperature reaching about 130 °C
consequence: The PE layer closes the pores and stops ion flow. The patent describes this as the intended shutdown. The article says the higher-melting PP layer of a tri-layer separator stays solid.
severity: moderate
source: volta-separators
where: Section on tri-layer separators and the abuse-event paragraph
side_effects: []
handling:
- text: 'Dry the pellets before processing: the Recythen data sheet gives a pre-drying temperature of 80 °C for 2 to 3 h, and a processing humidity of 0.15 % or less, for injection molding and extrusion.'
source: recythen-hdpe
where: Processing recommendations table
mitigations: []
uses:
- application: batteries
device: Microporous separator between the electrodes of a lithium-ion cell
example: The patent describes a shutdown separator 'typically used in lithium ion rechargeable cells', made of polyethylene.
source: patent-us6749961
where: Background of the Invention
- application: structures
device: Injection-molded plastic parts
example: H5818J is described as a general purpose HDPE resin suitable for injection molding.
source: scg-h5818j
where: Product description
supply:
- subject: Polyethylene
abundance: not searched
producers: []
critical_lists: []
recycling: The Recythen data sheet names a recycled-content HDPE grade, but gives no recycled percentage.
substitutes: []
source: recythen-hdpe
where: Product name and certifications section
documents:
- title: Product page, SCG Chemicals grade H5818J (general purpose HDPE, injection molding)
type: datasheet
url: https://www.scgchemicals.com/en/products-grade/h5818j
- title: Recythen HDPE data sheet (Interseroh), material data center entry
type: datasheet
url: https://materialdatacenter.com/ms/en/Recythen/Interseroh+Dienstleistungs+GmbH/recythen®+HDPE/b74b37cd/6918
- title: Pertachem HDPE product table (pipe grade and other grades)
type: datasheet
url: https://pertachem.com/hdpe-en
- title: Braskem Utec 3041 PE-UHMW data sheet (via Material Data Center)
type: datasheet
url: https://materialdatacenter.com/ms/en/Utec/Braskem/Utec®+3041/7517bb03/487
- title: ChemicalBook polyethylene MSDS, CAS 9002-88-4 (reseller-hosted SDS page)
type: sds
url: https://www.chemicalbook.com/msds/polyethylene.htm
- title: US 6,749,961 B1, Shutdown battery separator made with a blend of polymer and oligomer
type: database
url: https://patents.google.com/patent/US6749961
- title: Lithium-ion battery separators and their role in safety (Volta Foundation article)
type: report
url: https://volta.foundation/lithium-ion-battery-separators-and-their-role-in-safety/
- title: Celgard 2325 25 um trilayer PP/PE/PP separator roll (reseller listing, read but not used for numbers)
type: datasheet
url: https://cambridge-energy-solutions-ltd.odoo.com/shop/celgard-2325-25um-trilayer-pp-pe-pp-separator-roll-1757
- title: NIST Atomic Weights and Isotopic Compositions
type: database
url: https://physics.nist.gov/cgi-bin/Compositions/stand_alone.pl?ele=C&ascii=html
year: 2026
gaps:
- Manufacturer SDS PDFs for polyethylene (NIST 2886 and others) returned unreadable binary; the CAS number and hazard data come from a reseller-hosted ChemicalBook SDS page.
- Atomic oxygen erosion yield of polyethylene on LDEF (about 3.97e-24 cm3/atom in a search snippet) was not read in a fetched page, so it is not entered.
- Celgard 2325 (PP/PE/PP trilayer) porosity 39 %, puncture 360 g and Gurley 620 s are on a reseller listing only; no manufacturer sheet was read, and the trilayer is not pure polyethylene, so they are not entered.
- Celanese GUR, TIVAR and Ensinger/IGEPA PE-UHMW datasheets were PDFs that returned no readable text; the UHMW values come from the Braskem Utec 3041 page on Material Data Center. No modulus or service temperature for Utec 3041 was printed on that page, so none is entered.
- Melt flow index for the H5818J grade (18 g/10 min at 190 °C, 2.16 kg, ASTM D1238) is printed on the SCG page but has no matching benchmark, so it is not entered.
- Radiation, outgassing (TML/CVCM), and atomic oxygen mass-loss data for polyethylene were not located in a readable source.
- Melting point of a virgin HDPE injection grade was not found in a readable source; the 128 °C value is from a pipe-grade table with flattened columns.
- 'Corrosion and ageing: no UV dose, exposure time or retained-property number for polyethylene was read in a fetched page. Search results gave carbonyl-index trends for UV-exposed PE films, but the pages that held them returned 403 or were not opened, so no figure is entered.'
- 'Recipe: the atomic weights are NIST standard-atomic-weight intervals read on the NIST pages. The C and H shares are computed from C2H4, not printed in a source.'
- 'Supply: no producer share, country split or polyethylene feedstock figure (ethylene from naphtha or ethane) was read in a fetched page in this pass.'
sources:
scg-h5818j:
title: SCG Chemicals product grade page, H5818J general purpose HDPE for injection molding
url: https://www.scgchemicals.com/en/products-grade/h5818j
kind: datasheet
license: Manufacturer product page (cited, not reproduced)
recythen-hdpe:
title: Recythen HDPE, Interseroh Dienstleistungs GmbH, material data center entry
url: https://materialdatacenter.com/ms/en/Recythen/Interseroh+Dienstleistungs+GmbH/recythen®+HDPE/b74b37cd/6918
kind: datasheet
license: Supplier data sheet (cited, not reproduced)
pertachem-hdpe:
title: Pertachem, HDPE product table
url: https://pertachem.com/hdpe-en
kind: datasheet
license: Supplier web page (cited, not reproduced)
utec-3041:
title: Braskem Utec 3041 PE-UHMW data sheet, Material Data Center entry
url: https://materialdatacenter.com/ms/en/Utec/Braskem/Utec®+3041/7517bb03/487
kind: datasheet
license: Manufacturer data sheet (cited, not reproduced)
chemicalbook-pe-sds:
title: ChemicalBook, polyethylene MSDS (CAS 9002-88-4)
url: https://www.chemicalbook.com/msds/polyethylene.htm
kind: datasheet
license: Web SDS page (cited, not reproduced)
patent-us6749961:
title: US 6,749,961 B1, Shutdown battery separator made with a blend of polymer and oligomer
url: https://patents.google.com/patent/US6749961
kind: web
license: Patent text (public record)
volta-separators:
title: Lithium-ion Battery Separators and their Role in Safety, Volta Foundation
url: https://volta.foundation/lithium-ion-battery-separators-and-their-role-in-safety/
kind: web
license: Web article (cited, not reproduced)
nist-atomic-weights:
title: NIST Atomic Weights and Isotopic Compositions (standard atomic weight intervals for C, H, N, O)
url: https://physics.nist.gov/cgi-bin/Compositions/stand_alone.pl?ele=C&ascii=html
year: 2026
kind: database
license: public domain (NIST)
note: 'Standard atomic weight intervals printed: C [12.0096, 12.0116]; H [1.00784, 1.00811]; N [14.00643, 14.00728]; O [15.99903, 15.99977]'
wiki-polyethylene:
title: Wikipedia, Polyethylene (repeat unit, HDPE/LDPE density and routes, ageing and chemical resistance)
url: https://en.wikipedia.org/wiki/Polyethylene
kind: web
license: CC BY-SA (Wikipedia)
note: 'HDPE density 0.941 g/cm3 or more; LDPE 0.910 to 0.940 g/cm3; (C2H4)n. Computed shares from C2H4 (28.05 g/mol): C 85.6 percent, H 14.4 percent'
wiki-uhmwpe:
title: Wikipedia, Ultra-high-molecular-weight polyethylene (molar mass, route, UV, oxidation, chemicals)
url: https://en.wikipedia.org/wiki/Ultra-high-molecular-weight_polyethylene
kind: web
license: CC BY-SA (Wikipedia)
note: Molar mass 2 to 6 million daltons; density 0.93 to 0.94 g/cm3
wiki-esc:
title: Wikipedia, Environmental stress cracking (polyethylene section and named tests)
url: https://en.wikipedia.org/wiki/Environmental_stress_cracking
kind: web
license: CC BY-SA (Wikipedia)
license: CC-BY-4.0
updated: '2026-10-18'
review:
status: draft
method: assistant
checked_values: 13
unreachable: 5
caveats: 6
note: 'Values were read by an AI assistant on 2026-10-18 from the web pages named in each entry. Unreachable as readable text: the NASA LDEF erosion paper, the NIST polyethylene SDS, the Celanese GUR and TIVAR datasheets, and the Ensinger and IGEPA PE-UHMW PDFs. Caveats: the PE-UHMW values are for one grade (Utec 3041) read from a Material Data Center copy of the Braskem sheet; the H5818J values are a single grade; the HDPE pipe melting value comes from a table with flattened columns; the separator shutdown and melting values come from a patent and an article, not a measurement; the Recythen tensile value does not say whether it is yield or break; the CAS and hazard data come from a reseller-hosted SDS page.'
story:
risk_groups:
- title: For people
lead: The sources read here do not describe health effects of polyethylene. The one SDS page read (ChemicalBook, CAS 9002-88-4) prints no signal word and no hazard statements.
level: 1
verdict: No hazard statements printed
points:
- label: Handling
line: The Recythen data sheet asks for pre-drying at 80 °C for 2 to 3 h before molding, and a processing humidity of 0.15 % or less.
- title: If it fails
lead: The failure route in the sources is thermal, inside a battery.
points:
- label: Separator shutdown
line: A patent describes shutdown of a polyethylene separator around 130 °C, and an article gives the PE layer a melting point of 135 °C.
- title: Handling and storage
points:
- label: Service limits
line: The PE-UHMW grade Utec 3041 is listed with a yield strength of 17 MPa and an elongation at break of 400 %, both by ISO 527.
why: 'Polyethylene is an ethylene polymer used in two very different ways. In a lithium-ion cell, a thin microporous polyethylene separator shuts down near 130 °C by closing its pores, which the patent describes as its purpose. In engineering, polyethylene is an injection-molded plastic: a general-purpose HDPE grade H5818J has a density of 0.959 g/cm3 and a tensile strength at yield of 290 kg/cm2, and a PE-UHMW grade (Braskem Utec 3041) has a density of 925 kg/m3, a yield strength of 17 MPa and an elongation at break of 400 %.'
uses:
- where: Battery separator
line: A polyethylene microporous separator sits between the electrodes of a lithium-ion cell. A PP/PE/PP tri-layer uses the PE layer as the shutdown layer, which melts at 135 °C per an industry article.
- where: Injection-molded parts
line: H5818J is a general-purpose HDPE resin for injection molding. The recycled Recythen grade is listed at 950 kg/m3.
can_do:
- label: Density
value: 0.959 g/cm3
benchmark: density
line: The virgin HDPE grade H5818J has a density of 0.959 g/cm3 (ASTM D 1505). The PE-UHMW grade Utec 3041 gives 925 kg/m3 (ASTM D 792).
- label: Yield strength
value: 17 MPa
benchmark: yield_strength
line: The Braskem Utec 3041 page gives a tensile strength at yield of 17 MPa (ISO 527), with an elongation at break of 400 %.
- label: Shutdown
value: 130 °C
benchmark: melting_point
line: A polyethylene microporous separator is described as shutting down at about 130 °C, with the shutdown to occur below 130 °C in the detailed description.
compare: 'Within this profile, the UHMW-PE grade is 925 kg/m3 and the virgin HDPE grade is 0.959 g/cm3, so the UHMW grade is the lighter of the two. The stiffness is not comparable across the two sources: H5818J gives a flexural modulus of 13000 kg/cm2, and the Recythen grade a tensile modulus of 800 MPa.'
compare_rows:
- scope: material
label: Density
benchmark: density
- scope: material
label: Yield strength
benchmark: yield_strength
handling:
- 'Dry the resin before molding: 80 °C for 2 to 3 h, with humidity at 0.15 % or less (Recythen).'
- Note the grade. The H5818J values are one grade, and the UHMW-PE values are typical values for an unnamed grade.
good_for:
- 'Light plastic parts: 0.959 g/cm3 for the virgin HDPE injection grade, and 925 kg/m3 for the PE-UHMW grade.'
- 'Tough, stretchy parts: the PE-UHMW grade elongates by 400 % before breaking.'
- 'Battery separator shutdown: a polyethylene layer closes the pores near 130 °C.'
watch_out:
- 'Heat: a polyethylene separator layer melts near 130 to 135 °C, and the Utec 3041 page gives no service temperature.'
- 'Stiffness: the flexural modulus of H5818J is 13000 kg/cm2, and no modulus was taken for the PE-UHMW grade.'
- 'Data gaps: no erosion yield in orbit, or outgassing value was found for this profile.'
verdict: Polyethylene is a light, tough plastic in its HDPE and UHMW forms, and the shutdown layer of many lithium-ion separators at about 130 °C. The sourced values are one virgin HDPE grade, a recycled HDPE, one PE-UHMW grade, and two separator statements. The orbital erosion and outgassing values are not in this profile.
recipe:
line: Polyethylene repeat unit -CH2-CH2-, formula (C2H4)n (Wikipedia, Polyethylene). HDPE is defined as density 0.941 g/cm3 or more and is made with chromium/silica (Phillips), Ziegler-Natta or metallocene catalysts. LDPE is 0.910 to 0.940 g/cm3 and is made by free-radical polymerisation. UHMWPE has a molar mass of about 2 to 6 million daltons (Wikipedia, UHMWPE), made by coordination polymerisation with very active catalysts at high ethylene pressure.
parts:
- name: Ethylene
symbol: C2H4
share_note: Single monomer, polymerised to the -CH2-CH2- repeat unit; atoms C2H4
role: Only monomer for all three grades; grade differences come from catalyst, pressure and molar mass.
- name: Carbon
symbol: C
atoms: 2
share_percent: 85.6
role: Standard atomic weight interval, NIST. Share computed from C2H4 (28.05 g/mol) with the NIST carbon value.
share_note: atomic_weight [12.0096, 12.0116]
- name: Hydrogen
symbol: H
atoms: 4
share_percent: 14.4
role: Standard atomic weight interval, NIST. Share computed from C2H4.
share_note: atomic_weight [1.00784, 1.00811]
References
Every number above carries a reference number. Click one to see the source and where in it the value comes from.