{
  "spore": "profile",
  "id": "pi-upilex-s",
  "spore_version": "0.2",
  "family": "polyimides",
  "name": "Upilex-S polyimide film (BPDA)",
  "abbreviation": "PI (Upilex-S)",
  "role": "flexible insulating film",
  "category": "polymers",
  "type": "polyimides",
  "summary": "Upilex-S is UBE's standard polyimide film, made from biphenyl tetracarboxylic dianhydride (BPDA) rather than the pyromellitic dianhydride used in Kapton. The UBE datasheet gives a tensile strength of 520 MPa and a density of 1.47 (x10^3 kg/m3) for 25 micrometre film at 25 degC. In low Earth orbit on MISSE 2 the film eroded at 9.22e-24 cm3/atom, about three times the Kapton HN rate in the same NASA table, so exposed Upilex-S needs a cover. The NASA erosion yield is from one flight record and the UBE values come from a manufacturer datasheet; no finished part was flown.\n",
  "best_for": "A thin, flexible, electrically insulating film with a very low coefficient of thermal expansion and no melting point, where dimensional stability over temperature matters more than atomic-oxygen resistance",
  "weakest_at": "Atomic-oxygen erosion in low Earth orbit (MISSE 2 erosion yield 9.22e-24 cm3/atom, the highest of the polyimides in the NASA table), so exposed film must be covered or coated",
  "identity": {
    "formula": "C22H10O4N2 (repeat unit, from NASA Table IV); BPDA-based polyimide",
    "cas": "",
    "designations": [],
    "source": "banks2008",
    "where": "Table IV lists PI (Upilex-S) with formula C22H10O4N2 and molecular weight 366.3320; NASA Table V gives the atom counts. The CAS number is not read in this run and is left blank."
  },
  "tags": {
    "environments": [
      "low-earth-orbit"
    ],
    "stresses": [
      "atomic-oxygen",
      "uv",
      "total-radiation-dose",
      "thermal-cycling",
      "vacuum-and-outgassing"
    ],
    "applications": [
      "electronics-and-chips",
      "thermal-control"
    ]
  },
  "properties": [
    {
      "benchmark": "density",
      "label": "Density (measured, MISSE 2 sample)",
      "value": 1.3866,
      "bound": "exact",
      "unit": "g/cm3",
      "scope": "material",
      "conditions": {
        "sample": "MISSE 2 PEACE Polymers film, dehydrated before measurement",
        "temperature": "not stated",
        "unit_in_source": "g/cm3"
      },
      "method": "Measured density reported by NASA (ref. 12 density method)",
      "status": "ground",
      "source": "banks2008",
      "where": "Table II, density column for PI (Upilex-S or US), value printed as 1.3866 g/cm3",
      "source_detail": {
        "title": "NASA/TM-2008-215490: Atomic Oxygen Erosion Yield Predictive Tool for Spacecraft Polymers in Low Earth Orbit (Banks, Backus, de Groh)",
        "id": "NASA/TM-2008-215490",
        "url": "https://ntrs.nasa.gov/citations/20090011780",
        "year": 2008,
        "kind": "report",
        "license": "public domain (US government work)"
      }
    },
    {
      "benchmark": "density",
      "label": "Density (datasheet, 25 um film)",
      "value": 1.47,
      "bound": "exact",
      "unit": "x10^3 kg/m3",
      "scope": "material",
      "conditions": {
        "product": "UPILEX-25S film, 25 micrometre",
        "temperature": "25 degC",
        "unit_in_source": "x10^3 kg/m3"
      },
      "method": "ASTM D1505, as printed in the UBE datasheet",
      "status": "ground",
      "source": "ube_upilex_s",
      "where": "Section (1) Mechanical properties, Density row; also repeated in Section (5) as 1.47 for UPILEX-25S",
      "source_detail": {
        "title": "UBE UPILEX-S polyimide film datasheet (English)",
        "id": "ube.com/upilex/catalog/pdf/upilex_s_e.pdf",
        "url": "https://ube.com/upilex/catalog/pdf/upilex_s_e.pdf",
        "kind": "datasheet",
        "license": "manufacturer document, linked not reproduced"
      }
    },
    {
      "benchmark": "ultimate_tensile_strength",
      "label": "Tensile strength at 25 degC",
      "value": 520,
      "bound": "exact",
      "unit": "MPa",
      "scope": "material",
      "conditions": {
        "product": "UPILEX-25S",
        "temperature": "25 degC",
        "film_thickness": "25 micrometre"
      },
      "method": "ASTM D882",
      "status": "ground",
      "source": "ube_upilex_s",
      "where": "Section (1) Mechanical properties, Tensile strength row, 25 degC column for UPILEX-25S",
      "source_detail": {
        "title": "UBE UPILEX-S polyimide film datasheet (English)",
        "id": "ube.com/upilex/catalog/pdf/upilex_s_e.pdf",
        "url": "https://ube.com/upilex/catalog/pdf/upilex_s_e.pdf",
        "kind": "datasheet",
        "license": "manufacturer document, linked not reproduced"
      }
    },
    {
      "benchmark": "ultimate_tensile_strength",
      "label": "Tensile strength at 300 degC",
      "value": 290,
      "bound": "exact",
      "unit": "MPa",
      "scope": "material",
      "conditions": {
        "product": "UPILEX-25S",
        "temperature": "300 degC"
      },
      "method": "ASTM D882",
      "status": "ground",
      "source": "ube_upilex_s",
      "where": "Section (1) Mechanical properties, Tensile strength row, 300 degC column for UPILEX-25S",
      "source_detail": {
        "title": "UBE UPILEX-S polyimide film datasheet (English)",
        "id": "ube.com/upilex/catalog/pdf/upilex_s_e.pdf",
        "url": "https://ube.com/upilex/catalog/pdf/upilex_s_e.pdf",
        "kind": "datasheet",
        "license": "manufacturer document, linked not reproduced"
      }
    },
    {
      "benchmark": "ultimate_tensile_strength",
      "label": "Tensile strength at -269 degC",
      "value": 740,
      "bound": "exact",
      "unit": "MPa",
      "scope": "material",
      "conditions": {
        "product": "UPILEX-25S",
        "temperature": "-269 degC"
      },
      "method": "ASTM D882",
      "status": "ground",
      "source": "ube_upilex_s",
      "where": "Section (1) Mechanical properties, Tensile strength row, -269 degC column for UPILEX-25S",
      "source_detail": {
        "title": "UBE UPILEX-S polyimide film datasheet (English)",
        "id": "ube.com/upilex/catalog/pdf/upilex_s_e.pdf",
        "url": "https://ube.com/upilex/catalog/pdf/upilex_s_e.pdf",
        "kind": "datasheet",
        "license": "manufacturer document, linked not reproduced"
      }
    },
    {
      "benchmark": "elongation",
      "label": "Elongation at 25 degC",
      "value": 40,
      "bound": "exact",
      "unit": "%",
      "scope": "material",
      "conditions": {
        "product": "UPILEX-25S",
        "temperature": "25 degC"
      },
      "method": "ASTM D882",
      "status": "ground",
      "source": "ube_upilex_s",
      "where": "Section (1) Mechanical properties, Elongation row, 25 degC column for UPILEX-25S",
      "source_detail": {
        "title": "UBE UPILEX-S polyimide film datasheet (English)",
        "id": "ube.com/upilex/catalog/pdf/upilex_s_e.pdf",
        "url": "https://ube.com/upilex/catalog/pdf/upilex_s_e.pdf",
        "kind": "datasheet",
        "license": "manufacturer document, linked not reproduced"
      }
    },
    {
      "benchmark": "elastic_modulus",
      "label": "Tensile modulus at 25 degC",
      "value": 9.1,
      "bound": "exact",
      "unit": "GPa",
      "scope": "material",
      "conditions": {
        "product": "UPILEX-25S",
        "temperature": "25 degC"
      },
      "method": "ASTM D882",
      "status": "ground",
      "source": "ube_upilex_s",
      "where": "Section (1) Mechanical properties, Tensile modulus row, 25 degC column for UPILEX-25S",
      "source_detail": {
        "title": "UBE UPILEX-S polyimide film datasheet (English)",
        "id": "ube.com/upilex/catalog/pdf/upilex_s_e.pdf",
        "url": "https://ube.com/upilex/catalog/pdf/upilex_s_e.pdf",
        "kind": "datasheet",
        "license": "manufacturer document, linked not reproduced"
      }
    },
    {
      "benchmark": "cte",
      "label": "Thermal linear expansion coefficient (50 to 200 degC)",
      "value": 12,
      "bound": "exact",
      "unit": "ppm/degC",
      "scope": "material",
      "conditions": {
        "product": "UPILEX-25S",
        "temperature_range": "50 to 200 degC",
        "heating_rate": "5 degC/min"
      },
      "method": "Fine linear dilatometer",
      "status": "ground",
      "source": "ube_upilex_s",
      "where": "Section (3) Thermal properties, Thermal linear expansion coefficient row, UPILEX-25S column",
      "source_detail": {
        "title": "UBE UPILEX-S polyimide film datasheet (English)",
        "id": "ube.com/upilex/catalog/pdf/upilex_s_e.pdf",
        "url": "https://ube.com/upilex/catalog/pdf/upilex_s_e.pdf",
        "kind": "datasheet",
        "license": "manufacturer document, linked not reproduced"
      }
    },
    {
      "benchmark": "heat_shrinkage",
      "label": "Heat shrinkage",
      "value": 0.05,
      "bound": "exact",
      "unit": "%",
      "scope": "material",
      "conditions": {
        "product": "UPILEX-25S",
        "temperature": "200 degC",
        "time": "2 h"
      },
      "method": "ASTM D1204",
      "status": "ground",
      "source": "ube_upilex_s",
      "where": "Section (3) Thermal properties, Heat shrinkage row, UPILEX-25S column",
      "source_detail": {
        "title": "UBE UPILEX-S polyimide film datasheet (English)",
        "id": "ube.com/upilex/catalog/pdf/upilex_s_e.pdf",
        "url": "https://ube.com/upilex/catalog/pdf/upilex_s_e.pdf",
        "kind": "datasheet",
        "license": "manufacturer document, linked not reproduced"
      }
    },
    {
      "benchmark": "specific_heat",
      "label": "Specific heat",
      "value": 1.13,
      "bound": "exact",
      "unit": "kJ/(kg.K)",
      "scope": "material",
      "conditions": {
        "product": "UPILEX film (grade not stated in the row)",
        "temperature": "not stated"
      },
      "method": "Differential scanning calorimeter",
      "status": "ground",
      "source": "ube_upilex_s",
      "where": "Section (3) Thermal properties, Specific heat row",
      "source_detail": {
        "title": "UBE UPILEX-S polyimide film datasheet (English)",
        "id": "ube.com/upilex/catalog/pdf/upilex_s_e.pdf",
        "url": "https://ube.com/upilex/catalog/pdf/upilex_s_e.pdf",
        "kind": "datasheet",
        "license": "manufacturer document, linked not reproduced"
      }
    },
    {
      "benchmark": "thermal_conductivity",
      "label": "Thermal conductivity (thickness direction)",
      "value": 0.29,
      "bound": "exact",
      "unit": "W/(m.K)",
      "scope": "material",
      "conditions": {
        "product": "UPILEX-S film (grade not stated in the row)",
        "direction": "thickness"
      },
      "method": "Laser flash method",
      "status": "ground",
      "source": "ube_upilex_s",
      "where": "Section (3) Thermal properties, Thermal conductivity row",
      "source_detail": {
        "title": "UBE UPILEX-S polyimide film datasheet (English)",
        "id": "ube.com/upilex/catalog/pdf/upilex_s_e.pdf",
        "url": "https://ube.com/upilex/catalog/pdf/upilex_s_e.pdf",
        "kind": "datasheet",
        "license": "manufacturer document, linked not reproduced"
      }
    },
    {
      "benchmark": "heat_life_temperature",
      "label": "Heat life (tensile strength basis, 20,000 h)",
      "value": 290,
      "bound": "exact",
      "unit": "degC",
      "scope": "material",
      "conditions": {
        "product": "UPILEX-S film (grade not stated in the row)",
        "time": "20000 h"
      },
      "method": "Fixed temperature method, tensile strength basis as printed",
      "status": "ground",
      "source": "ube_upilex_s",
      "where": "Section (3) Thermal properties, Heat life (Tensile strength) row",
      "source_detail": {
        "title": "UBE UPILEX-S polyimide film datasheet (English)",
        "id": "ube.com/upilex/catalog/pdf/upilex_s_e.pdf",
        "url": "https://ube.com/upilex/catalog/pdf/upilex_s_e.pdf",
        "kind": "datasheet",
        "license": "manufacturer document, linked not reproduced"
      }
    },
    {
      "benchmark": "oxygen_index",
      "label": "Oxygen index",
      "value": 66,
      "bound": "exact",
      "unit": "%",
      "scope": "material",
      "conditions": {
        "product": "UPILEX-S film (grade not stated in the row)"
      },
      "method": "JIS K7201",
      "status": "ground",
      "source": "ube_upilex_s",
      "where": "Section (3) Thermal properties, Oxygen index row",
      "source_detail": {
        "title": "UBE UPILEX-S polyimide film datasheet (English)",
        "id": "ube.com/upilex/catalog/pdf/upilex_s_e.pdf",
        "url": "https://ube.com/upilex/catalog/pdf/upilex_s_e.pdf",
        "kind": "datasheet",
        "license": "manufacturer document, linked not reproduced"
      }
    },
    {
      "benchmark": "dielectric_strength",
      "label": "Dielectric strength at 25 degC",
      "value": 6.8,
      "bound": "exact",
      "unit": "kV",
      "scope": "material",
      "conditions": {
        "product": "UPILEX-25S",
        "temperature": "25 degC",
        "frequency": "60 Hz"
      },
      "method": "ASTM D149",
      "status": "ground",
      "source": "ube_upilex_s",
      "where": "Section (2) Electrical properties, Dielectric strength row, UPILEX-25S 25 degC",
      "source_detail": {
        "title": "UBE UPILEX-S polyimide film datasheet (English)",
        "id": "ube.com/upilex/catalog/pdf/upilex_s_e.pdf",
        "url": "https://ube.com/upilex/catalog/pdf/upilex_s_e.pdf",
        "kind": "datasheet",
        "license": "manufacturer document, linked not reproduced"
      }
    },
    {
      "benchmark": "dielectric_constant",
      "label": "Dielectric constant at 25 degC",
      "value": 3.5,
      "bound": "exact",
      "unit": "-",
      "scope": "material",
      "conditions": {
        "product": "UPILEX-25S",
        "temperature": "25 degC",
        "frequency": "1 kHz"
      },
      "method": "ASTM D150",
      "status": "ground",
      "source": "ube_upilex_s",
      "where": "Section (2) Electrical properties, Dielectric constant row, 1kHz, 25 degC",
      "source_detail": {
        "title": "UBE UPILEX-S polyimide film datasheet (English)",
        "id": "ube.com/upilex/catalog/pdf/upilex_s_e.pdf",
        "url": "https://ube.com/upilex/catalog/pdf/upilex_s_e.pdf",
        "kind": "datasheet",
        "license": "manufacturer document, linked not reproduced"
      }
    },
    {
      "benchmark": "dissipation_factor",
      "label": "Dissipation factor at 25 degC",
      "value": 0.0013,
      "bound": "exact",
      "unit": "-",
      "scope": "material",
      "conditions": {
        "product": "UPILEX-25S",
        "temperature": "25 degC",
        "frequency": "1 kHz"
      },
      "method": "ASTM D150",
      "status": "ground",
      "source": "ube_upilex_s",
      "where": "Section (2) Electrical properties, Dissipation factor row, 1kHz, 25 degC",
      "source_detail": {
        "title": "UBE UPILEX-S polyimide film datasheet (English)",
        "id": "ube.com/upilex/catalog/pdf/upilex_s_e.pdf",
        "url": "https://ube.com/upilex/catalog/pdf/upilex_s_e.pdf",
        "kind": "datasheet",
        "license": "manufacturer document, linked not reproduced"
      }
    },
    {
      "benchmark": "moisture_absorption",
      "label": "Water absorption (23 degC, 24 h immersion)",
      "value": 1.4,
      "bound": "exact",
      "unit": "%",
      "scope": "material",
      "conditions": {
        "temperature": "23 degC",
        "time": "24 h",
        "condition": "water immersion"
      },
      "method": "ASTM D570",
      "status": "ground",
      "source": "ube_upilex_s",
      "where": "Section (4) Chemical-resistant properties, Water absorption row, 23 degC 24h water immersion",
      "source_detail": {
        "title": "UBE UPILEX-S polyimide film datasheet (English)",
        "id": "ube.com/upilex/catalog/pdf/upilex_s_e.pdf",
        "url": "https://ube.com/upilex/catalog/pdf/upilex_s_e.pdf",
        "kind": "datasheet",
        "license": "manufacturer document, linked not reproduced"
      }
    },
    {
      "benchmark": "atomic_oxygen_erosion_yield",
      "label": "Atomic oxygen erosion yield (LEO, MISSE 2)",
      "value": 9.22e-24,
      "bound": "exact",
      "unit": "cm3/atom",
      "scope": "material",
      "conditions": {
        "environment": "low Earth orbit, ISS, MISSE 2 PEACE tray (outside Quest airlock)",
        "atomic_oxygen_fluence": "8.43e21 atoms/cm2",
        "exposure_duration": "about 4 years (2001 to 2005)"
      },
      "method": "Mass loss with carefully dehydrated mass measurement, density from Table II, erosion yield per NASA TM-2008-215490",
      "status": "flight",
      "source": "banks2008",
      "where": "Table I, MISSE 2 PEACE polymers erosion yield, row PI (Upilex-S or US); fluence from section 2.1",
      "source_detail": {
        "title": "NASA/TM-2008-215490: Atomic Oxygen Erosion Yield Predictive Tool for Spacecraft Polymers in Low Earth Orbit (Banks, Backus, de Groh)",
        "id": "NASA/TM-2008-215490",
        "url": "https://ntrs.nasa.gov/citations/20090011780",
        "year": 2008,
        "kind": "report",
        "license": "public domain (US government work)"
      }
    },
    {
      "benchmark": "ash_content",
      "label": "Ash content (mass fraction, Na)",
      "value": 0.000482,
      "bound": "exact",
      "unit": "-",
      "scope": "material",
      "conditions": {
        "sample": "MISSE 2 PEACE Polymers film"
      },
      "method": "RF plasma asher, as described in NASA TM-2008-215490",
      "status": "ground",
      "source": "banks2008",
      "where": "Table II, mass fraction of polymer that is ash, row PI (Upilex-S or US)",
      "source_detail": {
        "title": "NASA/TM-2008-215490: Atomic Oxygen Erosion Yield Predictive Tool for Spacecraft Polymers in Low Earth Orbit (Banks, Backus, de Groh)",
        "id": "NASA/TM-2008-215490",
        "url": "https://ntrs.nasa.gov/citations/20090011780",
        "year": 2008,
        "kind": "report",
        "license": "public domain (US government work)"
      }
    }
  ],
  "corrosion": [
    {
      "environment": "Low Earth orbit atomic oxygen (ISS, MISSE 2)",
      "headline": "Atomic oxygen erodes Upilex-S at 9.22e-24 cm3/atom, the highest erosion yield among the polyimides in the NASA MISSE 2 table.",
      "effect": "Over the MISSE 2 flight the polymer lost material at 9.22e-24 cm3/atom. For comparison, the NASA table gives 3.00e-24 for Kapton H and 2.81e-24 for Kapton HN. Exposed film must be covered or coated.",
      "rating": "severe",
      "conditions": {
        "fluence": "8.43e21 atoms/cm2",
        "duration": "about 4 years"
      },
      "source": "banks2008",
      "where": "Table I row PI (Upilex-S or US); Table I rows PI (Kapton H) and PI (Kapton HN); section 2.1"
    },
    {
      "environment": "Solar and charged-particle exposure (MISSE 2)",
      "headline": "NASA's ground-simulation comparison covers Upilex-S, but no Upilex-S absorptance number was read in this run.",
      "effect": "NASA's comparison of proton, electron and ultraviolet simulation discusses Kapton and Upilex S together; the Upilex-S absorptance change is not reproduced here.",
      "rating": "low",
      "conditions": {
        "exposure": "ISS MISSE 2, total equivalent sun hours 5000 to 6700 ESH"
      },
      "source": "banks2008",
      "where": "Section 2.1 (equivalent sun hours); the solar absorptance comparison is not reproduced here"
    },
    {
      "environment": "Chemical bath (acids, alkalis, hot water)",
      "headline": "Strength falls to 80 percent after 5 days in 10 percent sodium hydroxide at 25 degC; hot water barely changes the film.",
      "effect": "UBE reports strength retention of 80 percent in 10% sodium hydroxide, 25 degC, 5 days immersion, and 95 percent in pH 1.0 water at 100 degC for 2 weeks. The datasheet says the film is insoluble in organic solvents and resists virtually all chemicals.",
      "rating": "low",
      "conditions": {
        "product": "UPILEX-25S",
        "test": "ASTM D882 retention after immersion"
      },
      "source": "ube_upilex_s",
      "where": "Section (4) Chemical-resistant properties, strength retention table"
    }
  ],
  "risks": {
    "hazards": [
      {
        "text": "Heated above 300 degC, the film gives off traces of residual DMAC, which forms carbon monoxide; above 500 degC it gives pyrolytic products. UBE advises ventilation so DMAC stays below 10 ppm and carbon monoxide below 100 ppm, and organic gas masks for fume exposure.",
        "ghs": [],
        "source": "ube_upilex_s",
        "where": "Section (6) Packing and handling precautions, handling note"
      },
      {
        "text": "UBE says the film is flame resistant (UL94 V-0, oxygen index 66 percent) but advises checking the supplier safety data sheet before use.",
        "ghs": [],
        "source": "ube_upilex_s",
        "where": "Section (3) Thermal properties, flammability row; Section (6) handling note"
      }
    ],
    "failure_risks": [
      {
        "mode": "Atomic oxygen in low Earth orbit removes the film at 9.22e-24…",
        "consequence": "Atomic oxygen in low Earth orbit removes the film at 9.22e-24 cm3/atom, so bare Upilex-S film does not survive a long LEO mission.",
        "source": "banks2008",
        "where": "Table I"
      }
    ],
    "side_effects": [],
    "handling": [
      {
        "text": "Use good ventilation when heating the film, because of residual DMAC and pyrolysis products above 300 degC.",
        "source": "ube_upilex_s",
        "where": "Section (6) handling precautions"
      }
    ],
    "mitigations": [
      {
        "text": "Cover or coat the film in LEO. The erosion yield in the NASA table is the reason; no cover or coating was tested in the fetched sources.",
        "source": "banks2008",
        "where": "Table I"
      }
    ]
  },
  "uses": [
    {
      "application": "electronics-and-chips",
      "device": "Flexible printed circuit and TAB-tape substrates",
      "example": "UBE says Upilex-S changes little in size when heated, which suits minute circuits in flexible printed circuit and TAB-tape substrates.",
      "source": "ube_upilex_s",
      "where": "Section (3) Thermal properties, intro paragraph"
    },
    {
      "application": "thermal-control",
      "device": "Carrier base and release film for high-temperature processing",
      "example": "UBE lists Upilex-S as a carrier base and releasing material because its outgassing is low.",
      "source": "ube_upilex_s",
      "where": "Section (6) Smooth surface, application examples"
    },
    {
      "application": "electronics-and-chips",
      "device": "Electrical insulation in high-temperature circuits",
      "example": "UBE says the electrical properties hardly change at 200 degC, with a dielectric strength of 6.8 kV at 25 degC and 60 Hz.",
      "source": "ube_upilex_s",
      "where": "Section (2) Electrical properties"
    }
  ],
  "supply": [
    {
      "subject": "Polyimide film (Upilex)",
      "abundance": "Monomer feedstock abundance was not read in a fetched page.",
      "producers": [
        {
          "country": "Japan"
        }
      ],
      "critical_lists": [],
      "recycling": "Not sourced.",
      "substitutes": [],
      "source": "ube_upilex_s",
      "where": "Cover page: UBE's BPDA monomer and UPILEX film grades"
    }
  ],
  "media": [],
  "documents": [
    {
      "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": "UBE UPILEX-S polyimide film datasheet",
      "type": "datasheet",
      "url": "https://ube.com/upilex/catalog/pdf/upilex_s_e.pdf"
    }
  ],
  "gaps": [
    "Atomic oxygen erosion for Upilex-S is one MISSE 2 flight value; the NASA predicted-vs-measured table (Table VII) prints 9.22e-25 for Upilex-S, which conflicts with Table I (9.22e-24). Table I is used here; the conflict is not resolved.",
    "Glass transition temperature for Upilex-S was not found in any fetched page.",
    "Density for the UBE datasheet row is printed as x10^3 kg/m3; the value is kept as printed and not converted.",
    "Supply country shares, production volumes and critical-mineral lists were not reached in this run.",
    "Hazard classification (GHS) and the supplier SDS were not read in this run.",
    "Story media and outgassing (NASA Goddard database) were not read in this run.",
    "Only three sources were reached in this run; the lithium standard asks for eight."
  ],
  "story": {
    "why": "Upilex-S is a polyimide made from biphenyl tetracarboxylic dianhydride (BPDA), a different monomer from the pyromellitic dianhydride used in Kapton. The NASA table gives the repeat unit as C22H10O4N2 with a molecular weight of 366.3320. UBE says the film has no melting point and the highest heat resistance of any plastic film it lists. The MISSE 2 flight erosion yield of 9.22e-24 cm3/atom is the largest of the polyimides NASA lists, so this is a film for ground or covered use.",
    "uses": [],
    "can_do": [
      {
        "label": "Strength",
        "line": "Insulate and carry fine circuits at temperatures from -269 degC to 300 degC, keep its size when heated (thermal linear expansion of 12 ppm/degC from 50 to 200 degC), and serve as a low-outgassing carrier film. It cannot protect itself from atomic oxygen in low Earth orbit.",
        "scope": "material"
      }
    ],
    "compare": "In the NASA MISSE 2 table, Upilex-S eroded at 9.22e-24 cm3/atom against 3.00e-24 for Kapton H and 2.81e-24 for Kapton HN. For exposed LEO use, Upilex-S should not be chosen over Kapton HN on this evidence. No metal or composite is compared in the fetched sources.",
    "compare_rows": [
      {
        "label": "Atomic oxygen erosion yield",
        "benchmark": "atomic_oxygen_erosion_yield",
        "scope": "material"
      },
      {
        "label": "Density",
        "benchmark": "density",
        "scope": "material"
      },
      {
        "label": "Thermal linear expansion coefficient",
        "benchmark": "cte",
        "scope": "material"
      }
    ],
    "handling": [
      "Keep the film covered in orbit. When heating above 300 degC, ventilate so DMAC and carbon monoxide stay below the UBE limits of 10 ppm and 100 ppm. Check the supplier safety data sheet before use."
    ],
    "good_for": [
      "Thin, flexible, electrically insulating layers that must keep their size over a wide temperature range, with a low coefficient of thermal expansion and low outgassing."
    ],
    "watch_out": [
      "Atomic oxygen in LEO erodes Upilex-S faster than Kapton, so bare film does not last. The 9.22e-24 value is one flight, and the NASA predicted-vs-measured table prints a conflicting figure."
    ],
    "verdict": "Upilex-S is a heat-stable polyimide insulator with a strong datasheet and a fast MISSE 2 erosion record. It is useful on the ground and under cover, and it is a poor choice for bare LEO exposure.",
    "recipe": {
      "line": "Repeat unit C22H10O4N2 from BPDA-based polycondensation (formula and molecular weight from NASA Table IV). The synthesis route and the monomer ratio were not read in this run.",
      "parts": [
        {
          "name": "Carbon",
          "symbol": "C",
          "role": "Backbone of the aromatic imide rings and the biphenyl units.",
          "atoms": 22,
          "atomic_weight": 12.011
        },
        {
          "name": "Hydrogen",
          "symbol": "H",
          "role": "Ring hydrogens on the aromatic units.",
          "atoms": 10,
          "atomic_weight": 1.008
        },
        {
          "name": "Oxygen",
          "symbol": "O",
          "role": "Carbonyl oxygens in the imide rings.",
          "atoms": 4,
          "atomic_weight": 15.999
        },
        {
          "name": "Nitrogen",
          "symbol": "N",
          "role": "Imide nitrogen linking the carbonyl pairs.",
          "atoms": 2,
          "atomic_weight": 14.007
        }
      ]
    },
    "risk_groups": [
      {
        "title": "Electronics and space engineers who need a thin, insulating film…",
        "points": []
      }
    ]
  },
  "updated": "2026-10-20",
  "review": {
    "status": "draft",
    "method": "assistant",
    "checked_values": 19,
    "unreachable": 6,
    "caveats": 3,
    "note": "Written by an AI assistant on 2026-10-20 from text extracted from the NASA TM-2008-215490 PDF and the UBE Upilex-S datasheet PDF, both fetched in this run. Wikipedia was read for composition and history only. Only three sources were reached; the rest of the lithium standard is listed in gaps."
  },
  "sources": {
    "banks2008": {
      "title": "NASA/TM-2008-215490: Atomic Oxygen Erosion Yield Predictive Tool for Spacecraft Polymers in Low Earth Orbit (Banks, Backus, de Groh)",
      "id": "NASA/TM-2008-215490",
      "url": "https://ntrs.nasa.gov/citations/20090011780",
      "year": 2008,
      "kind": "report",
      "license": "public domain (US government work)"
    },
    "ube_upilex_s": {
      "title": "UBE UPILEX-S polyimide film datasheet (English)",
      "id": "ube.com/upilex/catalog/pdf/upilex_s_e.pdf",
      "url": "https://ube.com/upilex/catalog/pdf/upilex_s_e.pdf",
      "kind": "datasheet",
      "license": "manufacturer document, linked not reproduced"
    },
    "wiki_polyimide": {
      "title": "Wikipedia: Polyimide (composition and history only)",
      "id": "en.wikipedia.org/wiki/Polyimide",
      "url": "https://en.wikipedia.org/wiki/Polyimide",
      "kind": "web",
      "license": "CC-BY-SA-4.0"
    }
  },
  "license": "CC-BY-4.0",
  "url": "https://spacemushroom.com/profiles/pi-upilex-s/"
}