{ "spore": "profile", "id": "ptfe", "spore_version": "0.2", "family": "fluoropolymers", "name": "Polytetrafluoroethylene", "abbreviation": "PTFE", "role": "low-friction insulating and chemically inert polymer", "category": "polymers", "type": "fluoropolymers", "summary": "PTFE (Teflon) is a soft, slippery fluoropolymer that is an excellent electrical insulator and works from -200 degC to +260 degC according to a vendor sheet. On the MISSE 2 flight it eroded under atomic oxygen at 1.42e-25 cm3/atom, about twenty times slower than Kapton H. Its weakness is radiation: NASA wire-insulation guidance from 1968 says PTFE irradiated in air becomes useless after one or two megarads, and a NASA Glenn study calls it much more radiation-sensitive than FEP.\n", "best_for": "A low-friction, electrically insulating, low-outgassing plastic that resists atomic oxygen far better than Kapton, PEEK or most hydrocarbon polymers", "weakest_at": "Ionizing radiation (it loses strength and stretch at megarad doses), low strength (23 to 27 MPa at room temperature) and heating above 300 degC, where it gives off toxic fumes", "identity": { "formula": "(-CF2-CF2-)n", "cas": "9002-84-0", "designations": [], "source": "utd-sds", "where": "Section 1.1 (polytetrafluoroethylene, CAS 9002-84-0); formula written out by Space Mushroom from the name and from the NASA tables, which list the repeat unit as C2F4" }, "tags": { "environments": [ "low-earth-orbit" ], "stresses": [ "atomic-oxygen", "total-radiation-dose", "thermal-cycling", "extreme-cold", "vacuum-and-outgassing" ], "applications": [ "electronics-and-chips", "cryogenic-fuel" ] }, "properties": [ { "benchmark": "density", "label": "Density (semi-finished PTFE)", "value": 2.17, "bound": "exact", "unit": "g/cm3", "scope": "material", "conditions": { "form": "solid tubing, semi-finished PTFE product", "manufacturer": "GAPI s.r.l., Italy", "sheet_date": "emission date 12/02/2007" }, "method": "Value printed in a manufacturer safety data sheet (the sheet shows 2,17 gr/cm3 with a decimal comma)", "status": "ground", "note": "A Proto Labs sheet gives 2.14-2.18 g/cm3 (ASTM D792) and a Plastics International sheet gives a specific gravity of 2.13-2.22 (ASTM D792). The NASA MISSE 2 report uses 2.1503 g/cm3 for the flown PTFE film.", "source": "utd-sds", "where": "Section 9 (Physical and chemical properties)", "source_detail": { "title": "Safety Data Sheet: Semifinished PTFE Products (GAPI s.r.l.; copy hosted by UT Dallas core facilities)", "id": "PTFE Rev. 01, emission date 12/02/2007", "url": "https://cores.research.utdallas.edu/files/2023/04/PTFE-MSDS.pdf", "year": 2007, "kind": "datasheet", "license": "manufacturer document, linked not reproduced" } }, { "benchmark": "density", "label": "Density range (machined PTFE stock)", "value": 2.14, "value_high": 2.18, "bound": "exact", "unit": "g/cm3", "scope": "material", "conditions": { "test_standard": "ASTM D792", "form": "CNC machining stock, supplier typical values" }, "method": "Typical-value range from a supplier material data sheet", "status": "ground", "note": "The sheet shows 2.14-2.18 g/cm3 in both its imperial and metric columns.", "source": "protolabs", "where": "Properties table (Density)", "source_detail": { "title": "Material data sheet: PTFE (Teflon), CNC machining (Proto Labs)", "id": "Proto Labs document 2026-026", "url": "https://www.protolabs.com/media/nrknfrcm/2026-026-cnc-material-data-sheet_ptfe-teflon.pdf", "year": 2026, "kind": "datasheet", "license": "supplier document, linked not reproduced" } }, { "benchmark": "density", "label": "Density used by NASA for the flown PTFE film", "value": 2.1503, "bound": "exact", "unit": "g/cm3", "scope": "material", "conditions": { "sample": "PTFE film flown on MISSE 2 PEACE Polymers", "ash_fraction": "2.98e-4" }, "method": "Density value listed in the NASA report for the erosion-yield calculation", "status": "ground", "source": "banks2008", "where": "Table II (polymer physical properties)", "source_detail": { "title": "Atomic Oxygen Erosion Yield Predictive Tool for Spacecraft Polymers in Low Earth Orbit", "id": "NASA/TM-2008-215490, NTRS 20090011780", "url": "https://ntrs.nasa.gov/citations/20090011780", "year": 2008, "kind": "report", "license": "public domain (NASA)" } }, { "benchmark": "tensile_strength_room_temperature", "label": "Tensile strength (room temperature, supplier typical)", "value": 23, "value_high": 27, "bound": "exact", "unit": "MPa", "scope": "material", "conditions": { "test_standard": "ISO 12086 / ISO 527 / ASTM D4894", "temperature": "room temperature, not stated on the sheet", "form": "CNC machining stock" }, "method": "Typical-value range from a supplier material data sheet (also printed as 3,335-3,917 psi)", "status": "ground", "note": "A Plastics International sheet gives 3,000-5,000 psi (ASTM D1457, D1708, D638) at 73 degF (23 degC). In the Southampton cryogenic tests the PTFE sheet gave a lower figure, 18.15 MPa at 2 mm/min.", "source": "protolabs", "where": "Properties table (Tensile Strength)", "source_detail": { "title": "Material data sheet: PTFE (Teflon), CNC machining (Proto Labs)", "id": "Proto Labs document 2026-026", "url": "https://www.protolabs.com/media/nrknfrcm/2026-026-cnc-material-data-sheet_ptfe-teflon.pdf", "year": 2026, "kind": "datasheet", "license": "supplier document, linked not reproduced" } }, { "benchmark": "elongation_at_break_supplier_typical", "label": "Elongation at break (supplier typical)", "value": 230, "bound": "lower", "unit": "%", "scope": "material", "conditions": { "test_standard": "ISO 12086 / ISO 527 / ASTM D4894", "form": "CNC machining stock" }, "method": "Minimum value printed in a supplier material data sheet (listed as 230% or more)", "status": "ground", "note": "A Plastics International sheet gives 300-500 percent (ASTM D1457, D1708, D638) at 73 degF (23 degC). The Southampton sheet specimen stretched about 303 percent at 2 mm/min.", "source": "protolabs", "where": "Properties table (Elongation at Break)", "source_detail": { "title": "Material data sheet: PTFE (Teflon), CNC machining (Proto Labs)", "id": "Proto Labs document 2026-026", "url": "https://www.protolabs.com/media/nrknfrcm/2026-026-cnc-material-data-sheet_ptfe-teflon.pdf", "year": 2026, "kind": "datasheet", "license": "supplier document, linked not reproduced" } }, { "benchmark": "tensile_strength_at_room_temperature", "label": "Tensile strength at room temperature (Southampton test)", "value": 18.15, "bound": "exact", "unit": "MPa", "scope": "material", "conditions": { "temperature": "room temperature (295 K)", "crosshead_speed": "2 mm/min (0.00159 /s)", "specimen": "dumbbell cut by waterjet from flat sheet, ISO 37 Type I profile, PTFE grade not stated" }, "method": "Tensile test in a cryogenic test rig (mean of repeats)", "status": "ground", "uncertainty": "standard deviation 0.49 MPa", "note": "Young's modulus 0.82 GPa and strain at break 302.96 percent in the same row. At 250 mm/min the strength was 19.23 MPa. In the same table at 2 mm/min PEEK gave 99.55 MPa and UHMWPE 31.99 MPa; in Table 2 at 77 K PEEK gave 198.14 MPa. This is a prefinal preprint.", "source": "wang2024", "where": "Table 1 (strain rate effects at room temperature)", "source_detail": { "title": "Evaluating the potential of thermoplastic polymers for cryogenic sealing applications: strain rate and temperature effects", "id": "arXiv:2406.01165 (pre-final version)", "url": "https://arxiv.org/abs/2406.01165", "year": 2024, "kind": "paper", "license": "CC BY-NC-ND 4.0" } }, { "benchmark": "min_service_temp", "label": "Lowest service temperature (supplier)", "value": -200, "bound": "exact", "unit": "degC", "scope": "material", "conditions": { "basis": "supplier-stated service range (printed as -328 degF)", "form": "CNC machining stock" }, "method": "Value printed in a supplier material data sheet; no test method is listed for it", "status": "ground", "note": "This is a stated limit, not a measured one. The Southampton tests found PTFE much stronger but far less stretchy at 77 K and 20 K (see the cryogenic strength entries).", "source": "protolabs", "where": "Properties table (Service Temperature min-max)", "source_detail": { "title": "Material data sheet: PTFE (Teflon), CNC machining (Proto Labs)", "id": "Proto Labs document 2026-026", "url": "https://www.protolabs.com/media/nrknfrcm/2026-026-cnc-material-data-sheet_ptfe-teflon.pdf", "year": 2026, "kind": "datasheet", "license": "supplier document, linked not reproduced" } }, { "benchmark": "max_service_temp", "label": "Highest service temperature (supplier)", "value": 260, "bound": "exact", "unit": "degC", "scope": "material", "conditions": { "basis": "supplier-stated service range (printed as +500 degF)", "form": "CNC machining stock" }, "method": "Value printed in a supplier material data sheet; no test method is listed for it", "status": "ground", "note": "A Plastics International sheet gives an upper service temperature of 500 degF for 20,000 h (UL746B). NASA TN D-4553 (1968) lists 260 degC as the maximum recommended continuous service temperature for Teflon TFE wire insulation.", "source": "protolabs", "where": "Properties table (Service Temperature min-max)", "source_detail": { "title": "Material data sheet: PTFE (Teflon), CNC machining (Proto Labs)", "id": "Proto Labs document 2026-026", "url": "https://www.protolabs.com/media/nrknfrcm/2026-026-cnc-material-data-sheet_ptfe-teflon.pdf", "year": 2026, "kind": "datasheet", "license": "supplier document, linked not reproduced" } }, { "benchmark": "max_service_temp", "label": "Highest continuous service temperature of Teflon TFE wire insulation (NASA, 1968)", "value": 260, "bound": "exact", "unit": "degC", "scope": "material", "conditions": { "use": "hook-up wire insulation for spacecraft", "basis": "maximum recommended continuous duty service temperature" }, "method": "Value stated in a NASA guide for selecting wire insulation (the same list gives 205 degC for Teflon FEP)", "status": "ground", "source": "nasa-tnd4553", "where": "Section on temperature characteristics (page 12)", "source_detail": { "title": "Criteria for Selection of Wire Insulations for Use in Space Applications (V. Krueger)", "id": "NASA TN D-4553, NTRS 19680018792", "url": "https://ntrs.nasa.gov/citations/19680018792", "year": 1968, "kind": "report", "license": "public domain (NASA)" } }, { "benchmark": "melting_point_semi_finished_ptfe", "label": "Melting point (semi-finished PTFE)", "value": 327, "value_high": 335, "bound": "exact", "unit": "degC", "scope": "material", "conditions": { "form": "semi-finished PTFE product", "note": "the sheet prints 327/335 degC" }, "method": "Value printed in a manufacturer safety data sheet", "status": "ground", "note": "The Plastics International sheet gives 621 degF (ASTM D3418), which converts to 327 degC (Space Mushroom conversion).", "source": "utd-sds", "where": "Section 9 (Melting Point)", "source_detail": { "title": "Safety Data Sheet: Semifinished PTFE Products (GAPI s.r.l.; copy hosted by UT Dallas core facilities)", "id": "PTFE Rev. 01, emission date 12/02/2007", "url": "https://cores.research.utdallas.edu/files/2023/04/PTFE-MSDS.pdf", "year": 2007, "kind": "datasheet", "license": "manufacturer document, linked not reproduced" } }, { "benchmark": "glass_transition_temperature", "label": "Glass transition temperature", "value": 170, "bound": "exact", "unit": "K", "scope": "material", "conditions": { "basis": "value quoted by the authors from other papers, not measured in the study", "comparison": "PEEK 416 K, UHMWPE 123 K" }, "method": "Quoted literature value in a discussion section", "status": "ground", "note": "The authors use it to explain why PTFE is ductile at room temperature but brittle at 77 K and 20 K, both below this temperature.", "source": "wang2024", "where": "Section 4 (Discussion)", "source_detail": { "title": "Evaluating the potential of thermoplastic polymers for cryogenic sealing applications: strain rate and temperature effects", "id": "arXiv:2406.01165 (pre-final version)", "url": "https://arxiv.org/abs/2406.01165", "year": 2024, "kind": "paper", "license": "CC BY-NC-ND 4.0" } }, { "benchmark": "cte", "label": "Coefficient of linear thermal expansion (supplier typical, near room temperature)", "value": 12, "value_high": 13, "bound": "exact", "unit": "x 10^-5 per degC", "scope": "material", "conditions": { "test_standard": "ASTM D696", "temperature_range": "not stated on the sheet", "form": "CNC machining stock" }, "method": "Typical-value range from a supplier material data sheet (equal to 120-130 ppm/K)", "status": "ground", "note": "Measured on a sheet in the Southampton study, expansion is strongly temperature dependent, from 8.28e-6 per K (20-50 K) to 103.06e-6 per K (200-295 K).", "source": "protolabs", "where": "Properties table (Coefficient of Linear Thermal Expansion)", "source_detail": { "title": "Material data sheet: PTFE (Teflon), CNC machining (Proto Labs)", "id": "Proto Labs document 2026-026", "url": "https://www.protolabs.com/media/nrknfrcm/2026-026-cnc-material-data-sheet_ptfe-teflon.pdf", "year": 2026, "kind": "datasheet", "license": "supplier document, linked not reproduced" } }, { "benchmark": "cte", "label": "Mean coefficient of linear thermal expansion, 200 to 295 K", "value": 103.06, "bound": "exact", "unit": "x 10^-6 per K", "scope": "material", "conditions": { "temperature_range": "200 to 295 K", "specimen": "PTFE sheet, grade not stated", "method_detail": "contraction measured between 20 K and 295 K" }, "method": "Linear CTE calculated from a measured contraction curve", "status": "ground", "uncertainty": "standard deviation 0.04", "note": "Other ranges in the same table: 8.28 (20-50 K), 25.28 (50-123 K) and 62.31 (123-200 K) x 10^-6 per K. Between 295 K and 20 K the PTFE contracted by about 1.7 percent, against 0.9 percent for PEEK (Section 3.2).", "source": "wang2024", "where": "Table 4; Section 3.2", "source_detail": { "title": "Evaluating the potential of thermoplastic polymers for cryogenic sealing applications: strain rate and temperature effects", "id": "arXiv:2406.01165 (pre-final version)", "url": "https://arxiv.org/abs/2406.01165", "year": 2024, "kind": "paper", "license": "CC BY-NC-ND 4.0" } }, { "benchmark": "ultimate_tensile_strength_at_77_k", "label": "Ultimate tensile strength at 77 K", "value": 86.22, "bound": "exact", "unit": "MPa", "scope": "material", "conditions": { "temperature": "77 K", "crosshead_speed": "2 mm/min", "specimen": "dumbbell cut from flat sheet by waterjet (ISO 37 Type I profile), PTFE grade not stated" }, "method": "Tensile test in a cryogenic test rig (mean of repeats)", "status": "ground", "uncertainty": "standard deviation 0.23 MPa", "note": "Young's modulus 5.71 GPa and strain at break 4.44 percent in the same row. This is a prefinal preprint.", "source": "wang2024", "where": "Table 2 (77 K)", "source_detail": { "title": "Evaluating the potential of thermoplastic polymers for cryogenic sealing applications: strain rate and temperature effects", "id": "arXiv:2406.01165 (pre-final version)", "url": "https://arxiv.org/abs/2406.01165", "year": 2024, "kind": "paper", "license": "CC BY-NC-ND 4.0" } }, { "benchmark": "ultimate_tensile_strength_at_20_k", "label": "Ultimate tensile strength at 20 K", "value": 82.32, "bound": "exact", "unit": "MPa", "scope": "material", "conditions": { "temperature": "20 K", "crosshead_speed": "2 mm/min", "specimen": "dumbbell cut from flat sheet by waterjet (ISO 37 Type I profile), PTFE grade not stated" }, "method": "Tensile test in a cryogenic test rig (mean of repeats)", "status": "ground", "uncertainty": "standard deviation 0.59 MPa", "note": "Strain at break was 2.51 percent, against 302.96 percent at room temperature. At 250 mm/min the 20 K strength was 92.78 MPa.", "source": "wang2024", "where": "Table 3 (20 K)", "source_detail": { "title": "Evaluating the potential of thermoplastic polymers for cryogenic sealing applications: strain rate and temperature effects", "id": "arXiv:2406.01165 (pre-final version)", "url": "https://arxiv.org/abs/2406.01165", "year": 2024, "kind": "paper", "license": "CC BY-NC-ND 4.0" } }, { "benchmark": "atomic_oxygen_erosion_yield", "value": 1.42e-25, "bound": "exact", "unit": "cm3/atom", "scope": "material", "conditions": { "experiment": "MISSE 2 PEACE polymers, exterior of the International Space Station", "exposure": "3.95 yr in low Earth orbit, 16 August 2001 to 30 July 2005", "fluence": "8.43e21 atoms/cm2", "comparison": "Kapton H polyimide measured 3.00e-24 cm3/atom in the same table" }, "method": "Mass-loss erosion yield from the MISSE 2 flight samples, as compiled in the NASA report", "status": "flight", "note": "The report's predictive tool gave 1.58e-25 cm3/atom for PTFE (Table VII). Density used was 2.1503 g/cm3 and ash fraction 2.98e-4 (Table II). The report says some stacked thin-film samples eroded through, so some listed yields are lower bounds; PTFE is listed without a greater-than sign.", "source": "banks2008", "where": "Table I (MISSE 2 PEACE polymers erosion yield data); Table VII; Section 2.1 for exposure", "source_detail": { "title": "Atomic Oxygen Erosion Yield Predictive Tool for Spacecraft Polymers in Low Earth Orbit", "id": "NASA/TM-2008-215490, NTRS 20090011780", "url": "https://ntrs.nasa.gov/citations/20090011780", "year": 2008, "kind": "report", "license": "public domain (NASA)" } }, { "benchmark": "outgassing_tml", "label": "Total mass loss, PTFE tubing (GSFC data reference GSC17398)", "value": 0, "bound": "exact", "unit": "% mass", "scope": "material", "conditions": { "specimen": "PTFE TUBING AS 20-065-1, manufacturer code ZEU", "test_standard": "NASA GSFC screening test, ASTM E595 type", "temperature": "398 K (125 degC), 24 h in vacuum", "acceptance": "TML at most 1.0 percent and CVCM at most 0.10 percent" }, "method": "Value printed in the NASA outgassing compilation; a finished commercial product, not a bulk resin", "status": "ground", "note": "Water vapour regained (WVR) was 0.00 percent in the same row. A second PTFE entry, TFE wire insulation (GSFC6086, manufacturer MSY), has TML 0.01, CVCM 0.00 and WVR 0.00 percent. Note that GSFC10661, which a Gund Company bulletin labels PTFE/FEP at 0.01/0.00/0.02, is listed in RP-1124 as TEFLON FEP TYPE A 5 MIL FILM, so it is not used here as PTFE.", "source": "rp1124", "where": "Section B alphabetical listing, entry PTFE TUBING AS 20-065-1; test method on page 2 of the introduction", "source_detail": { "title": "Outgassing Data for Selecting Spacecraft Materials (Campbell and Scialdone)", "id": "NASA Reference Publication 1124, Revision 3, NTRS 19940017416", "url": "https://ntrs.nasa.gov/citations/19940017416", "year": 1993, "kind": "database", "license": "public domain (NASA)" } }, { "benchmark": "outgassing_cvcm", "label": "Collected volatile condensable material, PTFE tubing (GSFC data reference GSC17398)", "value": 0, "bound": "exact", "unit": "% mass", "scope": "material", "conditions": { "specimen": "PTFE TUBING AS 20-065-1, manufacturer code ZEU", "test_standard": "NASA GSFC screening test, ASTM E595 type", "temperature": "398 K (125 degC), 24 h in vacuum" }, "method": "Value printed in the NASA outgassing compilation", "status": "ground", "note": "The TFE wire insulation entry (GSFC6086) also shows CVCM 0.00 percent.", "source": "rp1124", "where": "Section B alphabetical listing, entry PTFE TUBING AS 20-065-1", "source_detail": { "title": "Outgassing Data for Selecting Spacecraft Materials (Campbell and Scialdone)", "id": "NASA Reference Publication 1124, Revision 3, NTRS 19940017416", "url": "https://ntrs.nasa.gov/citations/19940017416", "year": 1993, "kind": "database", "license": "public domain (NASA)" } }, { "benchmark": "weight_loss_of_teflon_tfe_insulated", "label": "Weight loss of Teflon TFE insulated wire in high vacuum, 100 h", "value": 0.04, "bound": "exact", "unit": "% mass", "scope": "material", "conditions": { "specimen": "Teflon TFE insulated wire, sample weight 2.0 g", "temperature": "212 degF (100 degC)", "time_in_vacuum": "100 hours" }, "method": "Weight loss in high vacuum, reported in NASA TN D-4553 from earlier work (its references 3 and 4)", "status": "ground", "note": "A second row gives 0.29 percent after 168 hours at 300 degF (149 degC). The report says gross weight losses of the insulations are small and acceptable, and mainly due to entrapped gases such as carbon dioxide and water.", "source": "nasa-tnd4553", "where": "Table 1", "source_detail": { "title": "Criteria for Selection of Wire Insulations for Use in Space Applications (V. Krueger)", "id": "NASA TN D-4553, NTRS 19680018792", "url": "https://ntrs.nasa.gov/citations/19680018792", "year": 1968, "kind": "report", "license": "public domain (NASA)" } }, { "benchmark": "elongation_lost_after_irradiation_in", "label": "Elongation lost after irradiation in high vacuum", "value": 88, "bound": "exact", "unit": "% of original elongation", "scope": "material", "conditions": { "dose": "8 megarads (Mrad)", "atmosphere": "high vacuum", "material": "Teflon TFE", "radiation": "ionizing radiation, type not stated in this passage" }, "method": "Statement in a NASA guide for selecting wire insulation (a literature summary)", "status": "ground", "note": "The same passage says that irradiated in air, Teflon TFE is quickly degraded and becomes useless after absorbing one or two megarads. 8 megarads equals 80 kGy. A dose tested, not a limit.", "source": "nasa-tnd4553", "where": "Section on radiation resistance", "source_detail": { "title": "Criteria for Selection of Wire Insulations for Use in Space Applications (V. Krueger)", "id": "NASA TN D-4553, NTRS 19680018792", "url": "https://ntrs.nasa.gov/citations/19680018792", "year": 1968, "kind": "report", "license": "public domain (NASA)" } }, { "benchmark": "dose_at_which_radiation_damage", "label": "Dose at which radiation damage becomes detectable (vendor summary)", "value": 20000, "value_high": 70000, "bound": "exact", "unit": "rad", "scope": "material", "conditions": { "atmosphere": "in air", "threshold": "first detectable mechanical damage", "vacuum_equivalent": "2-7 x 10^5 rad or more in vacuum" }, "method": "Summary table in a Rogers Corporation technical article, compiled from literature references dated 1951 to 1969", "status": "ground", "note": "2 to 7 x 10^4 rad is 200 to 700 Gy. In the same table 50 percent of tensile strength is retained at 10^6 rad in air and 10^7 rad or more in vacuum, and 100 percent elongation is retained to 2-5 x 10^5 rad in air and 2-5 x 10^6 rad in vacuum. The article says damage is smaller in vacuum because oxygen takes part in the damaging reactions. The source is a vendor article about PTFE-filled laminates; the table layout in the PDF is partly ambiguous, so only the clear rows are quoted.", "source": "rogers-radiation", "where": "Page 1, summary table of radiation doses related to damage levels", "source_detail": { "title": "The Effect of Nuclear Radiation Exposure to RT/duroid PTFE-Based Composites", "id": "Rogers Corporation publication 92-293, revised 081123", "url": "https://www.RogersCorp.com/-/media/project/rogerscorp/documents/advanced-electronics-solutions/english/properties---detailed-characteristics/the-effect-of-exposure-of-rt-duroid-ptfe-based-composites-to-nuclear-radiation.pdf", "year": 2023, "kind": "web", "license": "manufacturer document, linked not reproduced" } }, { "benchmark": "dielectric_constant", "label": "Dielectric constant", "value": 2.1, "bound": "exact", "unit": "dimensionless", "scope": "material", "conditions": { "basis": "typical value in a supplier sheet", "temperature": "73 degF (23 degC)", "test_method": "not listed for this row" }, "method": "Typical value printed in a supplier material data sheet", "status": "ground", "note": "The sheet says the dielectric constant and loss factor are low and stable across a wide temperature and frequency range.", "source": "plasticsintl", "where": "Introductory text", "source_detail": { "title": "Teflon PTFE (Polytetrafluoroethylene) data sheet (Plastics International)", "id": "Plastics International PTFE data sheet", "url": "https://www.plasticsintl.com/media/trshlm53/ptfe-data-sheet.pdf", "year": 2023, "kind": "datasheet", "license": "supplier document, linked not reproduced" } }, { "benchmark": "dielectric_strength", "label": "Dielectric strength", "value": 30, "value_high": 45, "bound": "exact", "unit": "kV/mm", "scope": "material", "conditions": { "test_standard": "ASTM D149", "specimen_thickness": "0.5 mm" }, "method": "Typical-value range from a supplier material data sheet (printed as 762-1,143 V/mil)", "status": "ground", "note": "Dielectric strength depends strongly on specimen thickness.", "source": "protolabs", "where": "Properties table (Dielectric Strength)", "source_detail": { "title": "Material data sheet: PTFE (Teflon), CNC machining (Proto Labs)", "id": "Proto Labs document 2026-026", "url": "https://www.protolabs.com/media/nrknfrcm/2026-026-cnc-material-data-sheet_ptfe-teflon.pdf", "year": 2026, "kind": "datasheet", "license": "supplier document, linked not reproduced" } }, { "benchmark": "volume_resistivity", "label": "Volume resistivity", "value": 100000000000000000, "value_high": 1000000000000000000, "bound": "exact", "unit": "ohm cm", "scope": "material", "conditions": { "test_standard": "ASTM D257", "form": "CNC machining stock" }, "method": "Typical-value range from a supplier material data sheet (printed as 10^17-10^18 ohm-cm)", "status": "ground", "note": "Surface resistivity is listed as 10^16-10^17 ohm.", "source": "protolabs", "where": "Properties table (Volume Resistivity)", "source_detail": { "title": "Material data sheet: PTFE (Teflon), CNC machining (Proto Labs)", "id": "Proto Labs document 2026-026", "url": "https://www.protolabs.com/media/nrknfrcm/2026-026-cnc-material-data-sheet_ptfe-teflon.pdf", "year": 2026, "kind": "datasheet", "license": "supplier document, linked not reproduced" } }, { "benchmark": "dynamic_coefficient_of_friction", "label": "Dynamic coefficient of friction (supplier typical, in air)", "value": 0.05, "value_high": 0.06, "bound": "exact", "unit": "dimensionless", "scope": "material", "conditions": { "test_standard": "ASTM D1894 / ASTM D3702", "atmosphere": "air, not vacuum" }, "method": "Typical-value range from a supplier material data sheet", "status": "ground", "note": "A Plastics International sheet gives 0.1 (ASTM D1894, below 10 ft/min). No vacuum friction value was found.", "source": "protolabs", "where": "Properties table (Dynamic Coefficient of Friction)", "source_detail": { "title": "Material data sheet: PTFE (Teflon), CNC machining (Proto Labs)", "id": "Proto Labs document 2026-026", "url": "https://www.protolabs.com/media/nrknfrcm/2026-026-cnc-material-data-sheet_ptfe-teflon.pdf", "year": 2026, "kind": "datasheet", "license": "supplier document, linked not reproduced" } }, { "benchmark": "limiting_oxygen_index", "label": "Limiting oxygen index", "value": 95, "bound": "lower", "unit": "% oxygen", "scope": "material", "conditions": { "test_standard": "ASTM D2863", "sheet_note": "printed as greater than 95 percent" }, "method": "Typical value printed in a supplier material data sheet", "status": "ground", "note": "The same sheet lists a UL94 flame rating of V-0 and a heat of combustion of 2,200 Btu/lb. This is a ground flammability screen in air, not the NASA-STD-6001 crew-safety test.", "source": "plasticsintl", "where": "Property table (Thermal section: Limiting Oxygen Index, Flame Rating)", "source_detail": { "title": "Teflon PTFE (Polytetrafluoroethylene) data sheet (Plastics International)", "id": "Plastics International PTFE data sheet", "url": "https://www.plasticsintl.com/media/trshlm53/ptfe-data-sheet.pdf", "year": 2023, "kind": "datasheet", "license": "supplier document, linked not reproduced" } } ], "corrosion": [ { "environment": "Atomic oxygen in low Earth orbit", "headline": "Atomic oxygen eroded PTFE about twenty times more slowly than Kapton H on the ISS.", "effect": "On the MISSE 2 flight PTFE had an erosion yield of 1.42e-25 cm3/atom, against 3.00e-24 for Kapton H and 2.99e-24 for PEEK in the same table. Other fluoropolymers were similar: FEP 2.00e-25 and PFA 1.73e-25.", "rating": "low", "conditions": { "flight": "MISSE 2, 3.95 yr, fluence 8.43e21 atoms/cm2" }, "source": "banks2008", "where": "Table I" }, { "environment": "Heat above 300 degC (decomposition)", "headline": "Overheated PTFE gives off toxic fumes.", "effect": "A PTFE safety data sheet says heating above 300 degC may release a fine particulate fume and, above 400 degC, decomposition products that can cause pulmonary inflammation, haemorrhage or oedema. Combustion or thermal decomposition gives very toxic and corrosive vapours such as hydrogen fluoride (HF) and carbonyl fluoride (COF2).", "rating": "severe", "conditions": { "trigger": "overheating or burning", "worst_case": "poor ventilation or confined spaces" }, "source": "utd-sds", "where": "Sections 3.1 to 3.6, 5.2 and 5.3" }, { "environment": "Chemicals and water", "headline": "The sheet says PTFE does not dissolve in water or organic solvents, but no corrosion test was opened.", "effect": "The semi-finished PTFE safety data sheet lists solubility as 'Not in water or in organic solvent' and the product as stable at normal temperatures and storage conditions. Suppliers describe PTFE as chemically resistant, but no quantitative chemical-resistance table was opened for this profile.", "rating": "unknown", "conditions": { "basis": "manufacturer safety data sheet, semi-finished PTFE products" }, "source": "utd-sds", "where": "Sections 9 and 10.1" } ], "risks": { "hazards": [ { "text": "Manufacturer safety data sheet (GAPI s.r.l., semi-finished PTFE, emission date 12/02/2007): the main hazard is inhaling fumes from overheating or burning. Heating above 300 degC may liberate a fine particulate fume that causes polymer fume fever, a flu-like illness with fever, chills, nausea and chest tightness. Symptoms are often delayed 4 to 24 hours and last 24 to 48 hours.", "ghs": [], "source": "utd-sds", "where": "Sections 3.1 to 3.3" }, { "text": "Above 400 degC, decomposition products may cause pulmonary inflammation, haemorrhage or oedema, particularly in poor ventilation or confined spaces. The sheet gives exposure limits for hydrofluoric acid (TLV 2.6 mg/m3) and carbonyl fluoride (TLV 5.4 mg/m3) during thermal decomposition.", "ghs": [], "source": "utd-sds", "where": "Sections 3.4, 3.5 and 8.1" }, { "text": "The solid is not classified as hazardous for transport, is described as not carcinogenic and as not toxic if swallowed. If a flame is applied it ignites but combustion stops when the flame is removed. Hydrogen fluoride fumes from a fire can react with water to form hydrofluoric acid.", "ghs": [], "source": "utd-sds", "where": "Sections 4.4, 5.2, 5.3, 11.2 and 14.1" } ], "failure_risks": [ { "mode": "Loss of strength and ductility under ionizing radiation", "trigger": "Absorbed doses of one to two megarads in air, or 8 megarads in high vacuum", "consequence": "In air Teflon TFE is quickly degraded and becomes useless after one or two megarads; in vacuum it loses 88 percent of its original elongation at 8 megarads. The primary effect is chain breaking, which lowers molecular weight and makes the plastic brittle.", "severity": "high", "source": "nasa-tnd4553", "where": "Section on radiation resistance" }, { "mode": "Surface cracking of ePTFE cable insulation on the ISS (predicted)", "trigger": "10-year mission with thermal cycling from -100 to 130 degC and ionizing radiation", "consequence": "A NASA Glenn analysis predicts an extremely embrittled front surface with cracks under any given strain, and microscopic cracks starting very early in the mission to a depth of about 0.030 cm after 10 years. This is a ground-based prediction, not a flight failure.", "severity": "moderate", "source": "degroh2005", "where": "Research summary, last paragraphs" }, { "mode": "Brittleness at hydrogen temperature", "trigger": "Cooling from room temperature to 20 K", "consequence": "At 2 mm/min strain at break fell from 302.96 percent at room temperature to 2.51 percent at 20 K, and the sheet contracted by about 1.7 percent between 295 K and 20 K.", "severity": "moderate", "source": "wang2024", "where": "Tables 1 and 3; Section 3.2" } ], "side_effects": [ { "text": "Irradiated polymers, almost without exception, release gaseous substances that may corrode spacecraft parts. In the report's mirror tests, vacuum-deposited copper and aluminium mirrors were sealed in ampoules with irradiated insulation, including Teflon TFE, and examined for corrosion.", "affects": "Nearby optics and metal surfaces", "source": "nasa-tnd4553", "where": "Section on corrosion of mirrors by evolved gases; Figures 1 and 2 (captions not read in detail, so no result for the Teflon TFE ampoules is stated)" }, { "text": "NASA Glenn describes PTFE as known to be significantly more susceptible to radiation degradation than FEP.", "affects": "Choice between PTFE and FEP for exposed insulation", "source": "degroh2005", "where": "Research summary, paragraph on the mobile transporter cable" } ], "handling": [ { "text": "Use usual protective clothing; avoid using the material at high temperature (the sheet says 280 degC) and take care to prevent inhalation of fume. No smoking while handling. Prevent burns from contact with hot material, hot surfaces and flames.", "source": "utd-sds", "where": "Sections 7.1, 7.2 and 10.2" }, { "text": "Store at normal temperatures; the product is stable under normal storage conditions. Treatment and disposal must follow local regulations, and recycling is suggested if possible.", "source": "utd-sds", "where": "Sections 10.1 and 13" } ], "mitigations": [ { "text": "Use local exhaust ventilation to remove vapours and fumes. Wear safety glasses, heat-resistant clothing and footwear, and a face shield if molten polymer might splash. In a fire, use self-contained breathing apparatus and full protective equipment.", "source": "utd-sds", "where": "Sections 5.2, 8.2 and 8.3" } ] }, "uses": [ { "application": "electronics-and-chips", "device": "Trailing umbilical cable insulation of the ISS Mobile Transporter (railcar), made of expanded PTFE", "example": "The cable outer jacket is six layers of expanded PTFE, about 43 mils thick after fabrication, with an inner core 7 to 10 mils thick; it has a 10-year mission life and was installed on the S0 truss during STS-110 in April 2002.", "source": "degroh2005", "where": "Research summary, paragraph on the mobile transporter" }, { "application": "electronics-and-chips", "device": "Spacecraft hook-up wire insulation (Teflon TFE and FEP)", "example": "NASA's 1968 selection guide compares Teflon TFE and FEP against polyolefin insulations for spacecraft wire, rating outgassing, radiation resistance and weight as the most important criteria.", "source": "nasa-tnd4553", "where": "Abstract; Table 1" }, { "application": "cryogenic-fuel", "device": "Candidate seal or liner material for liquid-hydrogen systems (ground tensile tests only)", "example": "Tensile and thermal-contraction tests at room temperature, 77 K and 20 K were run on PTFE, PEEK and UHMWPE to judge thermoplastics as alternatives to metal seals in cryogenic fuel systems.", "source": "wang2024", "where": "Abstract and Section 1" }, { "application": "electronics-and-chips", "device": "PTFE film flight sample on the exterior of the ISS (MISSE 2 PEACE Polymers experiment)", "example": "PTFE was one of 40 polymers flown to measure atomic oxygen erosion; the passport misse2-ptfe records the same exposure.", "source": "banks2008", "where": "Abstract and Table I" } ], "supply": [ { "subject": "Fluorine feedstock (fluorspar, calcium fluoride)", "producers": [ { "country": "China", "share_percent": 60, "year": 2025 }, { "country": "Mexico", "share_percent": 15, "year": 2025 }, { "country": "Mongolia", "share_percent": 15, "year": 2025 }, { "country": "South Africa", "share_percent": 4.1, "year": 2025 } ], "critical_lists": [], "recycling": "USGS: synthetic fluorspar may be produced from neutralization of waste in uranium enrichment, petroleum alkylation and stainless-steel pickling, though impurities constrain its use. Primary aluminum producers recycle HF and fluorides from smelting.", "substitutes": [ "USGS: fluosilicic acid from phosphate rock has been used as an alternative to fluorspar in making AlF3 and HF (about 73,000 tons of fluorspar equivalent was recovered in 2025)." ], "source": "usgs-mcs2026-fluorspar", "where": "World Mine Production and Reserves table, 2025e. Shares are calculated by Space Mushroom against the printed world total of 10,000 thousand t; the listed rows sum to 10,235, so shares are approximate. Recycling and Substitutes sections. Context: acid-grade fluorspar is mostly used to make anhydrous HF, the primary feedstock for fluoropolymers. US imports 2021-24 came from Mexico 64 percent, Vietnam 12 percent, China 10 percent, South Africa 9 percent; US net import reliance was 100 percent in 2025e." }, { "subject": "PTFE resin producers", "producers": [], "critical_lists": [], "substitutes": [], "source": "wiki-ptfe", "where": "Wikipedia PTFE page: Chemours is named as the maker of the PTFE-based Teflon brand. Daikin (Neoflon) and AGC (Fluon) were named in the brief, but their fetched Wikipedia pages do not state that they make PTFE, so they are not listed. No country shares for PTFE resin makers were found." } ], "media": [], "documents": [ { "title": "Mineral Commodity Summaries 2026: Fluorspar (USGS)", "type": "report", "url": "https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-fluorspar.pdf", "year": 2026 }, { "title": "NASA/TM-2008-215490: Atomic Oxygen Erosion Yield Predictive Tool for Spacecraft Polymers in Low Earth Orbit", "type": "report", "url": "https://ntrs.nasa.gov/citations/20090011780", "year": 2008 }, { "title": "NASA TN D-4553: Criteria for Selection of Wire Insulations for Use in Space Applications", "type": "report", "url": "https://ntrs.nasa.gov/citations/19680018792", "year": 1968 }, { "title": "NASA RP-1124 Rev. 3: Outgassing Data for Selecting Spacecraft Materials", "type": "report", "url": "https://ntrs.nasa.gov/citations/19940017416", "year": 1993 }, { "title": "Hubble Space Telescope Degradation Data Used for Ground-Based Durability Projection of Insulation on the International Space Station (NASA Glenn research summary)", "type": "report", "url": "https://ntrs.nasa.gov/citations/20050192335", "year": 2005 }, { "title": "Evaluating the potential of thermoplastic polymers for cryogenic sealing applications (arXiv preprint)", "type": "paper", "url": "https://arxiv.org/abs/2406.01165", "year": 2024 }, { "title": "Safety data sheet: semi-finished PTFE products (GAPI s.r.l.)", "type": "sds", "url": "https://cores.research.utdallas.edu/files/2023/04/PTFE-MSDS.pdf", "year": 2007 }, { "title": "The Effect of Nuclear Radiation Exposure to RT/duroid PTFE-Based Composites (Rogers Corporation)", "type": "datasheet", "url": "https://www.RogersCorp.com/-/media/project/rogerscorp/documents/advanced-electronics-solutions/english/properties---detailed-characteristics/the-effect-of-exposure-of-rt-duroid-ptfe-based-composites-to-nuclear-radiation.pdf", "year": 2023 } ], "gaps": [ "No thermal conductivity value for PTFE was opened and read; search snippets mentioned 0.20 and 0.34 W/(m K) from other datasheets but those pages were not read, so none is entered.", "No NASA outgassing database (outgassing.nasa.gov) entry was queried. The outgassing values come from NASA RP-1124 Revision 3 (1993), which lists finished PTFE products (tubing, wire insulation), not a bulk virgin-resin specimen. The database's current value for bulk PTFE was not read.", "No PTFE ultraviolet or vacuum-ultraviolet exposure result was found with a number. The NASA Goddard EOIM-III comparison report that was opened covers silvered Teflon (FEP-type) and not PTFE.", "No flown PTFE mechanical-property result (strength or elongation after orbital exposure) was found; the ISS mobile transporter cable result is a ground-based prediction in a short NASA research summary.", "No gamma or proton dose-versus-property curve for PTFE from a primary paper was opened; radiation numbers come from a 1968 NASA guide and a vendor summary of older literature, and the type of radiation behind the 8 Mrad figure is not stated in the NASA passage.", "No friction or wear value in vacuum was found; the friction values are in air.", "No PubChem compound record or ECHA/GHS classification for PTFE was opened, so hazards rest on one manufacturer safety data sheet from 2007 and carry no GHS codes. Other PTFE safety data sheets seen only in search snippets were not entered.", "Not entered: a quantitative chemical-resistance table, water absorption, the USGS critical-mineral status of fluorspar, and the trade-name or filled-PTFE grades.", "Daikin and AGC were named in the brief, but their fetched Wikipedia pages do not state that they make PTFE, so they are not listed as PTFE producers.", "The grade and manufacturer of the PTFE sheet in the Southampton preprint is not stated, and the Proto Labs, Plastics International and GAPI figures are supplier typical values, not certified grade data." ], "story": { "why": "Polytetrafluoroethylene (PTFE) is a polymer, a material made of very long chains of repeating units. Each unit is two carbon atoms each holding two fluorine atoms, written (-CF2-CF2-). Fluorine bonds very tightly to carbon and the fluorine coats the chain like a smooth sheath, which is why PTFE is famously slippery, chemically inert and a very good electrical insulator. A supplier sheet gives a density of about 2.17 g/cm3 (dense for a plastic), a dielectric constant of 2.1 and a volume resistivity of 10^17 to 10^18 ohm cm. PTFE melts at about 327 °C and a supplier lists a working range from -200 °C to +260 °C. The price of that tight bonding is that the chain is held together only weakly from one chain to the next, so PTFE is soft (23 to 27 MPa tensile strength) and, unlike most polymers, it is sensitive to ionizing radiation. In low Earth orbit it survives atomic oxygen well, but radiation snips the chains and leaves it brittle.", "uses": [ { "where": "ISS railcar cable", "line": "The trailing umbilical cables of the ISS Mobile Transporter use an outer jacket of six layers of expanded PTFE, about 43 mils thick, with an inner core of 7 to 10 mils. The cable has a 10-year mission life and was installed in April 2002." }, { "where": "Spacecraft wire insulation", "line": "NASA's 1968 selection guide compared Teflon TFE and FEP with polyolefin insulations for spacecraft wire, ranking outgassing, radiation resistance and weight as the most important criteria." }, { "where": "Tested on the ground for hydrogen systems", "line": "Researchers at Southampton tested PTFE in tension at room temperature, 77 K and 20 K to judge it as an alternative to metal seals in cryogenic fuel systems. These were laboratory tests, not a seal in service." }, { "where": "Flown on the ISS as film", "line": "PTFE film was one of 40 polymers flown on the exterior of the ISS in the MISSE 2 experiment to measure atomic oxygen erosion over 3.95 years." } ], "can_do": [ { "label": "Atomic oxygen", "line": "On the MISSE 2 flight PTFE eroded at 1.42 × 10⁻²⁵ cm³/atom, at a fluence of 8.43e21 atoms/cm², against 3.00 × 10⁻²⁴ for Kapton H in the same table.", "scope": "material", "value": "1.42e-25 cm3/atom" }, { "label": "Outgassing", "line": "Outgassing is the release of trapped gases and volatile compounds in vacuum, which can then condense on optics and sensors. NASA's outgassing compilation lists a PTFE tubing product at 0.00% total mass loss (TML) and 0.00% condensable material (CVCM) after 24 hours at 125 °C in vacuum, and a PTFE wire insulation at 0.01% and 0.00%. These are finished products, not bulk resin.", "scope": "material", "value": "0.00% in the NASA listing" }, { "label": "Heat", "line": "A safety data sheet gives a melting point of 327 to 335 °C, and a supplier lists a service range of -200 °C to +260 °C. NASA's 1968 guide lists 260 °C as the maximum continuous service temperature of Teflon TFE wire insulation.", "scope": "material", "value": "Melts at 327 °C" }, { "label": "Electrical insulation", "line": "A supplier sheet gives a volume resistivity of 10^17 to 10^18 ohm cm, a dielectric strength of 30 to 45 kV/mm (0.5 mm specimen, ASTM D149) and a dielectric constant of 2.1.", "scope": "material", "value": "10^17 to 10^18 ohm cm" }, { "label": "Low temperature", "line": "In tensile tests at 2 mm/min PTFE reached 18.15 MPa at room temperature, 86.22 MPa at 77 K and 82.32 MPa at 20 K. Strain at break fell to 4.44 percent at 77 K and 2.51 percent at 20 K, so it is much stronger but brittle when cold.", "scope": "material", "value": "86.22 MPa at 77 K" } ], "compare": "In low Earth orbit PTFE eroded at 1.42 × 10⁻²⁵ cm³/atom, against 2.99 × 10⁻²⁴ for PEEK and 3.00 × 10⁻²⁴ for Kapton H in the same flight table; FEP measured 2.00 × 10⁻²⁵. In a room-temperature tension test at 2 mm/min PTFE reached 18.15 MPa, against 99.55 MPa for PEEK and 31.99 MPa for UHMWPE in the same study, and at 77 K it reached 86.22 MPa against 198.14 MPa for PEEK. For radiation, NASA Glenn describes PTFE as significantly more susceptible to radiation degradation than FEP.", "compare_rows": [ { "label": "Density", "benchmark": "density", "scope": "material" }, { "label": "Max service temp", "benchmark": "max_service_temp", "scope": "material" }, { "label": "Glass transition temperature", "benchmark": "glass_transition_temperature", "scope": "material" } ], "handling": [ "The solid is not classified as hazardous for transport, but never heat it above 300 °C without ventilation.", "Fumes from overheated PTFE cause polymer fume fever; above 400 °C they can injure the lungs.", "Do not smoke while handling it, and use local exhaust ventilation where it is heated.", "Fire gives hydrogen fluoride fumes, so use self-contained breathing apparatus." ], "good_for": [ "Atomic oxygen resistance. The MISSE 2 erosion yield was 1.42 × 10⁻²⁵ cm³/atom, far below Kapton H at 3.00 × 10⁻²⁴.", "Electrical insulation. A supplier sheet gives a dielectric constant of 2.1 and a volume resistivity of 10^17 to 10^18 ohm cm.", "Low outgassing. NASA's listing shows PTFE tubing at 0.00% total mass loss and 0.00% condensable material after 24 hours at 125 °C.", "A very wide temperature range. A supplier lists -200 °C to +260 °C." ], "watch_out": [ "Radiation. NASA TN D-4553 says Teflon TFE becomes useless after one or two megarads in air, and loses 88 percent of its elongation at 8 megarads in vacuum.", "Softness. Tensile strength is only 23 to 27 MPa at room temperature.", "Brittle when cold. Strain at break fell from 302.96 percent at room temperature to 2.51 percent at 20 K.", "Overheating. Heating above 300 °C releases fumes, and above 400 °C toxic gases including hydrogen fluoride." ], "verdict": "PTFE is a slippery, low-outgassing, electrically excellent plastic that resists atomic oxygen far better than most polymers, but it is soft and ionizing radiation breaks it down at doses of a few megarads. It suits shielded or short-exposure uses such as cable insulation, not a long-lived exposed surface. Only the MISSE 2 erosion yield here is a flight result; the radiation and cold figures are ground tests or literature summaries.", "recipe": { "line": "PTFE is made by free-radical polymerization of one monomer, tetrafluoroethylene (TFE, C2F4), initiated with persulfate such as potassium or ammonium persulfate (Wikipedia). Granular PTFE is made by suspension polymerization in water with agitation and often a surfactant; PTFE is also made by emulsion polymerization, where a surfactant keeps the polymer dispersed in water. TFE can explosively decompose to tetrafluoromethane and carbon, so the reaction needs special apparatus to prevent hot spots.", "parts": [ { "name": "Carbon", "symbol": "C", "role": "The two backbone carbons of each repeat unit, bonded to each other.", "atoms": 2, "atomic_weight": 12.011 }, { "name": "Fluorine", "symbol": "F", "role": "Two fluorines on each backbone carbon.", "atoms": 4, "atomic_weight": 18.998 } ] }, "risk_groups": [ { "title": "For people", "lead": "The solid is described as not toxic, but heating PTFE above 300 °C can make you ill and above 400 °C can injure the lungs.", "points": [ { "label": "The solid", "line": "A manufacturer safety data sheet (emission date 12/02/2007) says the solid is not classified as hazardous for transport, is not carcinogenic and is not toxic if swallowed. It ignites if a flame is applied, but combustion stops when the flame is removed." }, { "label": "Polymer fume fever", "line": "Heating PTFE above 300 °C may release a fine fume that causes polymer fume fever, a flu-like illness with fever, chills, nausea and chest tightness. Symptoms are often delayed 4 to 24 hours and last 24 to 48 hours." }, { "label": "Hotter than 400 °C", "line": "Above 400 °C the decomposition products may cause pulmonary inflammation, haemorrhage or oedema, especially in poor ventilation or confined spaces. Combustion gives very toxic and corrosive vapours such as hydrogen fluoride and carbonyl fluoride." } ], "level": 2, "verdict": "Safe as a solid; toxic fumes if overheated" }, { "title": "If it fails", "lead": "These results come from a 1968 NASA guide, a NASA Glenn prediction and laboratory tests, not from a reported failure of a flown PTFE part.", "points": [ { "label": "Under radiation", "line": "NASA TN D-4553 says Teflon TFE irradiated in air becomes useless after one or two megarads, and in high vacuum loses 88 percent of its elongation at 8 megarads. Radiation breaks the long molecular chains, so the plastic turns brittle." }, { "label": "In orbit", "line": "A NASA Glenn study of the expanded PTFE cable on the ISS predicts a badly embrittled front surface, with cracks starting early and reaching about 0.030 cm deep after a 10-year mission. This is a ground-based prediction." }, { "label": "At hydrogen temperature", "line": "In tensile tests at 2 mm/min, PTFE strain at break fell from 302.96 percent at room temperature to 2.51 percent at 20 K, so the sheet went from stretchy to brittle." } ] }, { "title": "Handling and storage", "points": [ { "label": "Keep it cool", "line": "The safety data sheet advises against using the material at high temperature (it says 280 °C), taking care to prevent inhaling fume, and not smoking while handling it." }, { "label": "Ventilate", "line": "Use local exhaust ventilation to remove fumes. In a fire wear self-contained breathing apparatus, because hydrogen fluoride fumes can react with water to form hydrofluoric acid." }, { "label": "Waste", "line": "The sheet says the solid is stable in normal storage and suggests recycling where possible, and disposal must follow local regulations." } ] } ] }, "updated": "2026-10-17", "review": { "status": "draft", "method": "assistant", "checked_values": 26, "unreachable": 2, "caveats": 8, "note": "Written by an AI assistant on 2026-10-17. All values were read in text extracted from the downloaded source PDFs (NASA TM, TN D-4553 and RP-1124, the Southampton preprint, the Proto Labs, Plastics International, GAPI and Rogers documents). RP-1124 is an OCR scan, so its PTFE rows were read from OCR text. 2 sources were not usable (the NASA outgassing database search page and a PubChem PTFE record). 8 values carry caveats noted in the file. No values were taken from memory." }, "sources": { "usgs-mcs2026-fluorspar": { "title": "Mineral Commodity Summaries 2026, Fluorspar (U.S. Geological Survey)", "id": "USGS MCS 2026, February 2026", "url": "https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-fluorspar.pdf", "year": 2026, "kind": "report", "license": "public domain (USGS)" }, "wiki-ptfe": { "title": "Polytetrafluoroethylene (Wikipedia)", "id": "Wikipedia article, accessed 2026-10-19; synthesis and manufacturer sections", "url": "https://en.wikipedia.org/wiki/Polytetrafluoroethylene", "year": 2026, "kind": "web", "license": "CC BY-SA 4.0" }, "nist-atomic-weights": { "title": "Atomic Weights and Isotopic Compositions for All Elements (NIST)", "id": "NIST composition tables, accessed 2026-10-19", "url": "https://physics.nist.gov/cgi-bin/Compositions/stand_alone.pl?ele=&all=all&ascii=html", "year": 2026, "kind": "database", "license": "public domain (NIST)" }, "utd-sds": { "title": "Safety Data Sheet: Semifinished PTFE Products (GAPI s.r.l.; copy hosted by UT Dallas core facilities)", "id": "PTFE Rev. 01, emission date 12/02/2007", "url": "https://cores.research.utdallas.edu/files/2023/04/PTFE-MSDS.pdf", "year": 2007, "kind": "datasheet", "license": "manufacturer document, linked not reproduced" }, "protolabs": { "title": "Material data sheet: PTFE (Teflon), CNC machining (Proto Labs)", "id": "Proto Labs document 2026-026", "url": "https://www.protolabs.com/media/nrknfrcm/2026-026-cnc-material-data-sheet_ptfe-teflon.pdf", "year": 2026, "kind": "datasheet", "license": "supplier document, linked not reproduced" }, "plasticsintl": { "title": "Teflon PTFE (Polytetrafluoroethylene) data sheet (Plastics International)", "id": "Plastics International PTFE data sheet", "url": "https://www.plasticsintl.com/media/trshlm53/ptfe-data-sheet.pdf", "year": 2023, "kind": "datasheet", "license": "supplier document, linked not reproduced" }, "banks2008": { "title": "Atomic Oxygen Erosion Yield Predictive Tool for Spacecraft Polymers in Low Earth Orbit", "id": "NASA/TM-2008-215490, NTRS 20090011780", "url": "https://ntrs.nasa.gov/citations/20090011780", "year": 2008, "kind": "report", "license": "public domain (NASA)" }, "nasa-tnd4553": { "title": "Criteria for Selection of Wire Insulations for Use in Space Applications (V. Krueger)", "id": "NASA TN D-4553, NTRS 19680018792", "url": "https://ntrs.nasa.gov/citations/19680018792", "year": 1968, "kind": "report", "license": "public domain (NASA)" }, "rp1124": { "title": "Outgassing Data for Selecting Spacecraft Materials (Campbell and Scialdone)", "id": "NASA Reference Publication 1124, Revision 3, NTRS 19940017416", "url": "https://ntrs.nasa.gov/citations/19940017416", "year": 1993, "kind": "database", "license": "public domain (NASA)" }, "degroh2005": { "title": "Hubble Space Telescope Degradation Data Used for Ground-Based Durability Projection of Insulation on the International Space Station", "id": "NASA Glenn research summary, NTRS 20050192335 (de Groh, Banks, Dever, Hodermarsky)", "url": "https://ntrs.nasa.gov/citations/20050192335", "year": 2005, "kind": "report", "license": "public domain (NASA)" }, "wang2024": { "title": "Evaluating the potential of thermoplastic polymers for cryogenic sealing applications: strain rate and temperature effects", "id": "arXiv:2406.01165 (pre-final version)", "url": "https://arxiv.org/abs/2406.01165", "year": 2024, "kind": "paper", "license": "CC BY-NC-ND 4.0" }, "rogers-radiation": { "title": "The Effect of Nuclear Radiation Exposure to RT/duroid PTFE-Based Composites", "id": "Rogers Corporation publication 92-293, revised 081123", "url": "https://www.RogersCorp.com/-/media/project/rogerscorp/documents/advanced-electronics-solutions/english/properties---detailed-characteristics/the-effect-of-exposure-of-rt-duroid-ptfe-based-composites-to-nuclear-radiation.pdf", "year": 2023, "kind": "web", "license": "manufacturer document, linked not reproduced" } }, "license": "CC-BY-4.0", "url": "https://spacemushroom.com/profiles/ptfe/" }