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]