{
  "spore": "profile",
  "id": "ep",
  "spore_version": "0.2",
  "family": "engineering-polymers",
  "name": "Epoxy (epoxide)",
  "abbreviation": "EP",
  "role": "thermosetting resin for coatings, adhesives and composite matrices",
  "category": "polymers",
  "type": "epoxies-and-resins",
  "summary": "Epoxies are reactive prepolymers that cure into a cross-linked thermoset network. The most common resin is bisphenol A diglycidyl ether (BADGE, DGEBA), made from bisphenol A and epichlorohydrin. In the NASA MISSE 2 flight tray, an epoxy sample eroded at 4.21e-24 cm3/atom under atomic oxygen in low Earth orbit, close to the 4.02e-24 cm3/atom predicted by NASA's erosion-yield tool.",
  "best_for": "Structural bonding and matrix resin where a rigid, chemically resistant cured network is needed (EPON 828 cures to tensile values above 69 MPa when unfilled)",
  "weakest_at": "Atomic oxygen and ultraviolet exposure in orbit: an erosion yield of 4.21e-24 cm3/atom, and UV ageing that cracks the surface and lowers hardness",
  "identity": {
    "formula": "Cross-linked epoxy network; repeat unit C20H19O3 (molar mass 307.3683 g/mol) as printed in the NASA TM polymer table",
    "designations": [],
    "source": "nasa-tm-2008-215490",
    "where": "Table IV (repeat unit formula and molar mass)"
  },
  "tags": {
    "environments": [
      "low-earth-orbit"
    ],
    "stresses": [
      "atomic-oxygen",
      "uv",
      "vacuum-and-outgassing"
    ],
    "applications": [
      "structures"
    ]
  },
  "properties": [
    {
      "benchmark": "atomic_oxygen_erosion_yield",
      "label": "Atomic oxygen erosion yield, MISSE 2 flight tray",
      "value": 4.21e-24,
      "bound": "exact",
      "unit": "cm3/atom",
      "scope": "material",
      "conditions": {
        "exposure": "MISSE 2 PEACE, ISS outside Quest airlock, 2001-08-16 to 2005-07-30",
        "fluence": "8.43e21 atoms/cm2"
      },
      "method": "Measured on flown samples; density and ash corrected by the NASA tool authors",
      "status": "flight",
      "source": "nasa-tm-2008-215490",
      "where": "Table I, row Epoxide or epoxy, MISSE 2 erosion yield column",
      "source_detail": {
        "title": "Atomic Oxygen Erosion Yield Predictive Tool for Spacecraft Polymers in Low Earth Orbit",
        "id": "NASA/TM-2008-215490 (Banks and Backus, December 2008)",
        "url": "https://ntrs.nasa.gov/citations/20090011780",
        "year": 2008,
        "kind": "report",
        "license": "CC-BY-4.0"
      }
    },
    {
      "benchmark": "atomic_oxygen_erosion_yield",
      "label": "Predicted atomic oxygen erosion yield (NASA tool)",
      "value": 4.02e-24,
      "bound": "exact",
      "unit": "cm3/atom",
      "scope": "material",
      "conditions": {
        "model": "NASA predictive tool, fitted to the MISSE 2 data"
      },
      "method": "Predicted by the NASA erosion-yield tool, compared with the measured value",
      "status": "calculated",
      "source": "nasa-tm-2008-215490",
      "where": "Table VII, row Epoxide or epoxy, predicted erosion yield column",
      "source_detail": {
        "title": "Atomic Oxygen Erosion Yield Predictive Tool for Spacecraft Polymers in Low Earth Orbit",
        "id": "NASA/TM-2008-215490 (Banks and Backus, December 2008)",
        "url": "https://ntrs.nasa.gov/citations/20090011780",
        "year": 2008,
        "kind": "report",
        "license": "CC-BY-4.0"
      }
    },
    {
      "benchmark": "density",
      "label": "Density, epoxy (NASA MISSE 2 polymer table)",
      "value": 1.115,
      "bound": "exact",
      "unit": "g/cm3",
      "scope": "material",
      "conditions": {
        "basis": "density used by the NASA tool, from supplier data (ref. 12 in the paper)"
      },
      "method": "Supplier information cited by the NASA paper; not a new measurement",
      "status": "ground",
      "source": "nasa-tm-2008-215490",
      "where": "Table II, row Epoxide or epoxy, Density column",
      "source_detail": {
        "title": "Atomic Oxygen Erosion Yield Predictive Tool for Spacecraft Polymers in Low Earth Orbit",
        "id": "NASA/TM-2008-215490 (Banks and Backus, December 2008)",
        "url": "https://ntrs.nasa.gov/citations/20090011780",
        "year": 2008,
        "kind": "report",
        "license": "CC-BY-4.0"
      }
    },
    {
      "benchmark": "ash_mass_fraction",
      "label": "Mass fraction that is ash (Na), epoxy",
      "value": 0.0334,
      "bound": "exact",
      "unit": "fraction",
      "scope": "material",
      "conditions": {
        "basis": "mass fraction of the polymer that is ash, measured for the NASA tool"
      },
      "method": "Measured by the NASA paper authors",
      "status": "ground",
      "source": "nasa-tm-2008-215490",
      "where": "Table II, row Epoxide or epoxy, mass fraction of ash column (printed 3.34e-2)",
      "source_detail": {
        "title": "Atomic Oxygen Erosion Yield Predictive Tool for Spacecraft Polymers in Low Earth Orbit",
        "id": "NASA/TM-2008-215490 (Banks and Backus, December 2008)",
        "url": "https://ntrs.nasa.gov/citations/20090011780",
        "year": 2008,
        "kind": "report",
        "license": "CC-BY-4.0"
      }
    },
    {
      "benchmark": "molar_mass",
      "label": "Repeat unit molar mass, epoxy",
      "value": 307.3683,
      "bound": "exact",
      "unit": "g/mol",
      "scope": "material",
      "conditions": {
        "formula": "C20H19O3"
      },
      "method": "Printed in the NASA paper table of repeat-unit structures",
      "status": "ground",
      "source": "nasa-tm-2008-215490",
      "where": "Table IV, row Epoxide or epoxy, atomic mass column",
      "source_detail": {
        "title": "Atomic Oxygen Erosion Yield Predictive Tool for Spacecraft Polymers in Low Earth Orbit",
        "id": "NASA/TM-2008-215490 (Banks and Backus, December 2008)",
        "url": "https://ntrs.nasa.gov/citations/20090011780",
        "year": 2008,
        "kind": "report",
        "license": "CC-BY-4.0"
      }
    },
    {
      "benchmark": "molar_mass",
      "label": "Molar mass, bisphenol A diglycidyl ether (BADGE)",
      "value": 340.4,
      "bound": "exact",
      "unit": "g/mol",
      "scope": "material",
      "conditions": {
        "formula": "C21H24O4"
      },
      "method": "Computed by PubChem from the molecular formula",
      "status": "calculated",
      "source": "pubchem-badge",
      "where": "Compound summary, Molecular Weight (CID 2286)",
      "source_detail": {
        "title": "Bisphenol A diglycidyl ether, PubChem compound summary",
        "id": "PubChem CID 2286",
        "url": "https://pubchem.ncbi.nlm.nih.gov/compound/2286",
        "year": 2026,
        "kind": "database",
        "license": "PubChem, public domain"
      }
    },
    {
      "benchmark": "epoxide_equivalent_weight",
      "label": "Epoxide equivalent weight, EPON Resin 828",
      "value": 185,
      "value_high": 192,
      "bound": "exact",
      "unit": "g/eq",
      "scope": "material",
      "conditions": {
        "grade": "EPON Resin 828 (uncured liquid resin)"
      },
      "method": "ASTM D1652, as printed on the manufacturer bulletin",
      "status": "ground",
      "source": "epon828-bulletin",
      "where": "Typical properties table, Epoxide Equivalent Weight row",
      "source_detail": {
        "title": "Technical Data Bulletin, EPON Resin 828 RP 3075",
        "id": "Hexion, reissued September 2005",
        "url": "https://www.spacematdb.com/spacemat/manudatasheets/Epon828.pdf",
        "year": 2005,
        "kind": "datasheet",
        "license": "manufacturer bulletin, cited"
      }
    },
    {
      "benchmark": "viscosity",
      "label": "Viscosity at 25 degC, EPON Resin 828",
      "value": 110,
      "value_high": 150,
      "bound": "exact",
      "unit": "P",
      "scope": "material",
      "conditions": {
        "temperature": "25 °C",
        "grade": "EPON Resin 828 (uncured liquid resin)"
      },
      "method": "ASTM D445, as printed on the manufacturer bulletin",
      "status": "ground",
      "source": "epon828-bulletin",
      "where": "Typical properties table, Viscosity @ 25 °C row",
      "source_detail": {
        "title": "Technical Data Bulletin, EPON Resin 828 RP 3075",
        "id": "Hexion, reissued September 2005",
        "url": "https://www.spacematdb.com/spacemat/manudatasheets/Epon828.pdf",
        "year": 2005,
        "kind": "datasheet",
        "license": "manufacturer bulletin, cited"
      }
    },
    {
      "benchmark": "density",
      "label": "Density at 25 degC, EPON Resin 828",
      "value": 1.16,
      "bound": "exact",
      "unit": "g/ml",
      "scope": "material",
      "conditions": {
        "temperature": "25 °C",
        "grade": "EPON Resin 828 (uncured liquid resin)"
      },
      "method": "Printed on the manufacturer bulletin",
      "status": "ground",
      "source": "epon828-bulletin",
      "where": "Typical properties table, Density @ 25 °C row",
      "source_detail": {
        "title": "Technical Data Bulletin, EPON Resin 828 RP 3075",
        "id": "Hexion, reissued September 2005",
        "url": "https://www.spacematdb.com/spacemat/manudatasheets/Epon828.pdf",
        "year": 2005,
        "kind": "datasheet",
        "license": "manufacturer bulletin, cited"
      }
    },
    {
      "benchmark": "refractive_index",
      "label": "Refractive index at 25 degC, EPON Resin 828",
      "value": 1.573,
      "bound": "exact",
      "unit": "dimensionless",
      "scope": "material",
      "conditions": {
        "temperature": "25 °C",
        "grade": "EPON Resin 828 (uncured liquid resin)"
      },
      "method": "Printed on the manufacturer bulletin",
      "status": "ground",
      "source": "epon828-bulletin",
      "where": "Typical properties table, Refractive index @ 25 °C row",
      "source_detail": {
        "title": "Technical Data Bulletin, EPON Resin 828 RP 3075",
        "id": "Hexion, reissued September 2005",
        "url": "https://www.spacematdb.com/spacemat/manudatasheets/Epon828.pdf",
        "year": 2005,
        "kind": "datasheet",
        "license": "manufacturer bulletin, cited"
      }
    },
    {
      "benchmark": "ultimate_tensile_strength",
      "label": "Tensile strength, unfilled cured EPON 828 systems",
      "value": 69,
      "bound": "exact",
      "unit": "MPa",
      "scope": "material",
      "conditions": {
        "basis": "printed as greater than 10,000 psi (69 MPa); a floor across curing agents, not a single result",
        "cure": "varies with curing agent"
      },
      "method": "Manufacturer statement on the bulletin",
      "status": "ground",
      "source": "epon828-bulletin",
      "where": "General information, curing section (Tensile values row)",
      "source_detail": {
        "title": "Technical Data Bulletin, EPON Resin 828 RP 3075",
        "id": "Hexion, reissued September 2005",
        "url": "https://www.spacematdb.com/spacemat/manudatasheets/Epon828.pdf",
        "year": 2005,
        "kind": "datasheet",
        "license": "manufacturer bulletin, cited"
      }
    },
    {
      "benchmark": "elastic_modulus",
      "label": "Modulus, unfilled cured EPON 828 systems",
      "value": 2750,
      "bound": "exact",
      "unit": "MPa",
      "scope": "material",
      "conditions": {
        "basis": "printed as greater than 400,000 psi (2750 MPa); a floor across curing agents"
      },
      "method": "Manufacturer statement on the bulletin",
      "status": "ground",
      "source": "epon828-bulletin",
      "where": "General information, curing section (modulus values sentence)",
      "source_detail": {
        "title": "Technical Data Bulletin, EPON Resin 828 RP 3075",
        "id": "Hexion, reissued September 2005",
        "url": "https://www.spacematdb.com/spacemat/manudatasheets/Epon828.pdf",
        "year": 2005,
        "kind": "datasheet",
        "license": "manufacturer bulletin, cited"
      }
    },
    {
      "benchmark": "shear_strength",
      "label": "Shear strength, EPON 828 bonded systems",
      "value": 41,
      "bound": "exact",
      "unit": "MPa",
      "scope": "material",
      "conditions": {
        "basis": "printed as up to 6,000 psi (41 MPa)"
      },
      "method": "Manufacturer statement on the bulletin",
      "status": "ground",
      "source": "epon828-bulletin",
      "where": "General information, adhesion sentence",
      "source_detail": {
        "title": "Technical Data Bulletin, EPON Resin 828 RP 3075",
        "id": "Hexion, reissued September 2005",
        "url": "https://www.spacematdb.com/spacemat/manudatasheets/Epon828.pdf",
        "year": 2005,
        "kind": "datasheet",
        "license": "manufacturer bulletin, cited"
      }
    },
    {
      "benchmark": "hardness",
      "label": "Leeb hardness, unaged epoxy resin (UV study)",
      "value": 860,
      "bound": "exact",
      "unit": "HLD",
      "scope": "material",
      "conditions": {
        "basis": "non-aged reference for the UV ageing series"
      },
      "method": "Leeb hardness as printed in the UV ageing study",
      "status": "ground",
      "source": "pmc11821137",
      "where": "Results, hardness section (non-aged value)",
      "source_detail": {
        "title": "Effect of Ultraviolet Aging on Properties of Epoxy Resin and Its Pultruded Fiber-Reinforced Composite",
        "id": "doi:10.3390/polym (Polymers, MDPI, 2025), PMC11821137",
        "url": "https://pmc.ncbi.nlm.nih.gov/articles/PMC11821137/",
        "year": 2025,
        "kind": "paper",
        "license": "CC BY 4.0"
      }
    },
    {
      "benchmark": "hardness",
      "label": "Leeb hardness, epoxy resin after 792 h UV ageing",
      "value": 838,
      "bound": "exact",
      "unit": "HLD",
      "scope": "material",
      "conditions": {
        "exposure": "UV-340 fluorescent lamp, 792 h"
      },
      "method": "Leeb hardness as printed in the UV ageing study",
      "status": "ground",
      "source": "pmc11821137",
      "where": "Results, hardness section (838 HLD at 792 h)",
      "source_detail": {
        "title": "Effect of Ultraviolet Aging on Properties of Epoxy Resin and Its Pultruded Fiber-Reinforced Composite",
        "id": "doi:10.3390/polym (Polymers, MDPI, 2025), PMC11821137",
        "url": "https://pmc.ncbi.nlm.nih.gov/articles/PMC11821137/",
        "year": 2025,
        "kind": "paper",
        "license": "CC BY 4.0"
      }
    },
    {
      "benchmark": "percent_strength_loss",
      "label": "Bending strength decrease, epoxy composite after UV ageing",
      "value": 6,
      "bound": "exact",
      "unit": "percent",
      "scope": "material",
      "conditions": {
        "basis": "CFRP pultruded composite with epoxy resin, not the neat resin; printed change from initial value",
        "exposure": "UV ageing, overhead-wire composite study"
      },
      "method": "Measured in the UV ageing study",
      "status": "ground",
      "source": "pmc11821137",
      "where": "Abstract, final sentence",
      "source_detail": {
        "title": "Effect of Ultraviolet Aging on Properties of Epoxy Resin and Its Pultruded Fiber-Reinforced Composite",
        "id": "doi:10.3390/polym (Polymers, MDPI, 2025), PMC11821137",
        "url": "https://pmc.ncbi.nlm.nih.gov/articles/PMC11821137/",
        "year": 2025,
        "kind": "paper",
        "license": "CC BY 4.0"
      }
    }
  ],
  "corrosion": [
    {
      "environment": "Ultraviolet radiation with oxygen and water (lab UV ageing, UV-340 lamp)",
      "headline": "UV ageing cracks the surface of epoxy resin and lowers hardness; the resin fails first at the surface.",
      "effect": "Photo-oxidation and chain scission cause weight change, colour deepening, microcracks and a loss of hardness. The study says UV aging predominantly affected the surface layer resin.",
      "rating": "moderate",
      "conditions": {
        "exposure": "UV-340 fluorescent lamp, up to 1080 h",
        "hardness_series": "860 HLD unaged, 838 HLD at 792 h"
      },
      "source": "pmc11821137",
      "where": "Abstract; Results, hardness section"
    },
    {
      "environment": "Atomic oxygen in low Earth orbit (MISSE 2, ISS, about 3.95 years)",
      "headline": "Epoxy eroded at 4.21e-24 cm3/atom, a moderate yield compared with other MISSE 2 polymers.",
      "effect": "A 4.21e-24 cm3/atom erosion yield after a fluence of 8.43e21 atoms/cm2. The 2.68e-24 polypropylene and 9.14e-24 POM values in the same table give the range.",
      "rating": "moderate",
      "conditions": {
        "fluence": "8.43e21 atoms/cm2",
        "exposure": "MISSE 2 PEACE, ISS, 2001 to 2005"
      },
      "source": "nasa-tm-2008-215490",
      "where": "Table I, row Epoxide or epoxy"
    }
  ],
  "risks": {
    "hazards": [
      {
        "text": "PubChem GHS summary for bisphenol A diglycidyl ether: causes skin irritation (H315), may cause an allergic skin reaction (H317) and causes serious eye irritation (H319), in more than 99.9% of notifications.",
        "ghs": [
          "H315",
          "H317",
          "H319"
        ],
        "source": "pubchem-badge",
        "where": "GHS Classification (CID 2286)"
      },
      {
        "text": "PubChem also lists toxic to aquatic life with long lasting effects (H411) in 50.9% of reports.",
        "ghs": [
          "H411"
        ],
        "source": "pubchem-badge",
        "where": "GHS Classification (CID 2286)"
      }
    ],
    "failure_risks": [
      {
        "mode": "Photo-oxidation under ultraviolet light cracks the surface and…",
        "consequence": "Photo-oxidation under ultraviolet light cracks the surface and reduces hardness.",
        "source": "pmc11821137",
        "where": "Results, hardness section"
      },
      {
        "mode": "Atomic oxygen erodes the surface in low Earth orbit at 4.21e-24…",
        "consequence": "Atomic oxygen erodes the surface in low Earth orbit at 4.21e-24 cm3/atom.",
        "source": "nasa-tm-2008-215490",
        "where": "Table I"
      }
    ],
    "side_effects": [],
    "handling": [
      {
        "text": "Wear gloves and eye protection; the GHS statements list skin irritation, sensitisation and eye irritation.",
        "source": "pubchem-badge",
        "where": "GHS Classification (CID 2286)"
      }
    ],
    "mitigations": []
  },
  "uses": [
    {
      "application": "structures",
      "device": "Structural adhesives and bonded joints",
      "example": "EPON 828 is cured with a range of hardeners to bond a broad range of substrates; cured systems show shear strength of up to 6,000 psi (41 MPa).",
      "source": "epon828-bulletin",
      "where": "General information and adhesion sentences"
    },
    {
      "application": "structures",
      "device": "Carbon fibre epoxy composite for overhead wires",
      "example": "A pultruded carbon fibre epoxy composite used in overhead wires lost 6.0% of its bending strength after UV ageing.",
      "source": "pmc11821137",
      "where": "Abstract"
    }
  ],
  "supply": [],
  "media": [],
  "documents": [
    {
      "title": "EPON Resin 828 technical data bulletin",
      "type": "datasheet",
      "url": "https://www.spacematdb.com/spacemat/manudatasheets/Epon828.pdf"
    }
  ],
  "gaps": [
    "No epoxy supply data (producers, shares, critical-mineral status) was read in this run; bisphenol A and epichlorohydrin production shares were not fetched.",
    "No epoxy-specific ageing data beyond UV and atomic oxygen, such as thermal ageing, humidity and chemical resistance, was read in this run.",
    "Only four sources were reached in this run; the lithium standard asks for 8 or more.",
    "Glass transition temperature and cure schedule for EPON 828 were not read from a fetched page; the search snippets were not used as values.",
    "Ash mass fraction and repeat-unit molar mass use non-canonical benchmark names (ash_mass_fraction, molar_mass)."
  ],
  "story": {
    "why": "Epoxies are used where a rigid, chemically resistant thermoset is needed. They cure into a cross-linked network that bonds well to many substrates. In the NASA MISSE 2 flight tray, the epoxy eroded at a moderate rate under atomic oxygen, and it cracks under UV ageing in the laboratory.",
    "uses": [
      {
        "where": "Structural bonding",
        "line": "EPON 828 bonds a broad range of substrates. Unfilled cured systems exceed 69 MPa in tensile strength and 2,750 MPa in modulus, as printed by the manufacturer."
      },
      {
        "where": "Composite overhead-wire component",
        "line": "A carbon fibre epoxy composite used in overhead wires was studied under UV ageing. The composite lost 6.0% of its bending strength."
      }
    ],
    "can_do": [
      {
        "label": "Erosion in orbit",
        "line": "The epoxy eroded at 4.21e-24 cm3/atom in the MISSE 2 flight tray, close to the 4.02e-24 cm3/atom predicted by NASA's erosion-yield tool.",
        "scope": "material",
        "value": "4.21e-24 cm3/atom"
      },
      {
        "label": "Density",
        "line": "The NASA table gives a density of 1.115 g/cm3 for the epoxy used in the erosion model.",
        "scope": "material",
        "value": "1.115 g/cm3"
      }
    ],
    "compare": "The epoxy sits in the middle of the MISSE 2 polymer set on erosion yield. The table compares it with polypropylene, polystyrene and polyoxymethylene using the same NASA data. Tensile and modulus values are manufacturer floors for unfilled cured EPON 828 and should not be read as a single test result.",
    "compare_rows": [
      {
        "label": "Density",
        "benchmark": "density",
        "scope": "material"
      },
      {
        "label": "Atomic oxygen erosion yield",
        "benchmark": "atomic_oxygen_erosion_yield",
        "scope": "material"
      },
      {
        "label": "Modulus",
        "benchmark": "elastic_modulus",
        "scope": "material"
      }
    ],
    "handling": [
      "Use gloves and eye protection; the uncured resin is an irritant and a sensitiser.",
      "Keep out of direct UV light, which cracks the cured surface."
    ],
    "good_for": [
      "Structural bonding where the cured network must resist chemicals and heat.",
      "Composite matrices for structural parts, as in the overhead-wire study."
    ],
    "watch_out": [
      "Atomic oxygen erodes epoxy in low Earth orbit at 4.21e-24 cm3/atom.",
      "UV ageing reduces surface hardness and cracks the resin."
    ],
    "verdict": "Epoxy is a rigid, well-bonding thermoset. It resists atomic oxygen better than some polymers in the MISSE 2 set, but it needs UV protection and handling care.",
    "recipe": {
      "line": "Most commercial epoxies are made by reacting bisphenol A with epichlorohydrin, then forming the glycidyl ether groups with sodium hydroxide, which removes the chlorine as sodium chloride. The liquid resin is then cured by a hardener that opens the epoxide rings and cross-links the network.",
      "parts": [
        {
          "name": "Bisphenol A",
          "symbol": "BPA",
          "role": "The diphenol that forms the backbone of the resin, from the reaction with epichlorohydrin."
        },
        {
          "name": "Epichlorohydrin",
          "symbol": "ECH",
          "role": "Supplies the epoxide (glycidyl) end groups, after dehydrochlorination with sodium hydroxide."
        }
      ]
    },
    "risk_groups": [
      {
        "title": "For people",
        "lead": "The uncured resin is classified as an irritant and a sensitiser by most reporters to PubChem.",
        "points": [
          {
            "label": "Skin and eyes",
            "line": "Causes skin irritation, may cause an allergic skin reaction and causes serious eye irritation, per PubChem's GHS summary."
          }
        ],
        "level": 0,
        "verdict": "Irritant and sensitiser"
      },
      {
        "title": "In orbit",
        "lead": "Epoxy is used in orbit only as a test material here.",
        "points": [
          {
            "label": "Atomic oxygen",
            "line": "Eroded at 4.21e-24 cm3/atom during about 3.95 years on the ISS, with a predicted value of 4.02e-24 cm3/atom."
          }
        ]
      }
    ]
  },
  "updated": "2026-10-20",
  "review": {
    "status": "draft",
    "method": "assistant",
    "checked_values": 16,
    "unreachable": 0,
    "caveats": 4,
    "note": "Written by an AI assistant from pages read in this run; 16 values, 4 sources. Supply, thermal ageing and the glass transition temperature were not found."
  },
  "sources": {
    "nasa-tm-2008-215490": {
      "title": "Atomic Oxygen Erosion Yield Predictive Tool for Spacecraft Polymers in Low Earth Orbit",
      "id": "NASA/TM-2008-215490 (Banks and Backus, December 2008)",
      "url": "https://ntrs.nasa.gov/citations/20090011780",
      "year": 2008,
      "kind": "report",
      "license": "CC-BY-4.0"
    },
    "epon828-bulletin": {
      "title": "Technical Data Bulletin, EPON Resin 828 RP 3075",
      "id": "Hexion, reissued September 2005",
      "url": "https://www.spacematdb.com/spacemat/manudatasheets/Epon828.pdf",
      "year": 2005,
      "kind": "datasheet",
      "license": "manufacturer bulletin, cited"
    },
    "pmc11821137": {
      "title": "Effect of Ultraviolet Aging on Properties of Epoxy Resin and Its Pultruded Fiber-Reinforced Composite",
      "id": "doi:10.3390/polym (Polymers, MDPI, 2025), PMC11821137",
      "url": "https://pmc.ncbi.nlm.nih.gov/articles/PMC11821137/",
      "year": 2025,
      "kind": "paper",
      "license": "CC BY 4.0"
    },
    "pubchem-badge": {
      "title": "Bisphenol A diglycidyl ether, PubChem compound summary",
      "id": "PubChem CID 2286",
      "url": "https://pubchem.ncbi.nlm.nih.gov/compound/2286",
      "year": 2026,
      "kind": "database",
      "license": "PubChem, public domain"
    }
  },
  "license": "CC-BY-4.0",
  "url": "https://spacemushroom.com/profiles/ep/"
}