{
  "spore": "profile",
  "id": "cfrp",
  "spore_version": "0.2",
  "family": "glass-and-composites",
  "name": "Carbon-fibre reinforced epoxy (CFRP)",
  "abbreviation": "CFRP",
  "role": "structural composite",
  "category": "composites",
  "type": "carbon-fiber-reinforced",
  "summary": "Carbon-fibre reinforced polymer is carbon fibre tows or fabric set in an epoxy matrix and cured into a laminate. The Hexcel HexPly 8552 prepreg with IM7 fibre is a 350 F cure, toughened epoxy system used in space launchers and space structures. Its unidirectional laminate reaches 2724 MPa tensile strength at 0 degrees (dry, 25 C), while a quasi-isotropic 25/50/25 layup gives 717 MPa.\n",
  "best_for": "Stiffness and strength per unit mass in structures: 164 GPa at 0 degrees in unidirectional IM7/8552 laminate",
  "weakest_at": "Strength across the fibres: 64 MPa at 90 degrees in unidirectional IM7/8552, and the epoxy limits service to about 121 C",
  "identity": {
    "formula": "Carbon fibre (T700S or IM7 tows) in an amine-cured toughened epoxy matrix; the example system is Hexcel HexPly 8552 (IM7 fibre), a prepreg with 33 to 38 % resin content for tapes",
    "designations": [],
    "source": "hexcel-8552",
    "where": "Description section and Typical Physical Properties table of the HexPly 8552 Product Data Sheet"
  },
  "tags": {
    "environments": [
      "low-earth-orbit"
    ],
    "stresses": [
      "thermal-cycling",
      "vacuum-and-outgassing"
    ],
    "applications": [
      "structures",
      "habitats-and-suits",
      "propulsion-and-tanks"
    ]
  },
  "properties": [
    {
      "benchmark": "density",
      "label": "Density of neat HexPly 8552 epoxy resin",
      "value": 1.3,
      "bound": "exact",
      "unit": "g/cm3",
      "scope": "material",
      "conditions": {
        "form": "unreinforced 8552 resin",
        "temperature": "not stated"
      },
      "method": "Value printed in a manufacturer datasheet, converted from 0.0470 lb/in3 (factor 27.68)",
      "status": "ground",
      "source": "hexcel-8552",
      "where": "Neat Resin Properties, row Density",
      "source_detail": {
        "title": "HexPly 8552 mid-toughened, high strength, damage-resistant, structural epoxy matrix, Product Data Sheet",
        "id": "Hexcel Corporation, Copyright 2020 (file uploaded 2026)",
        "url": "https://www.hexcel.com/wp-content/uploads/2026/01/HexPly_8552_us_DataSheet-1.pdf",
        "year": 2020,
        "kind": "datasheet",
        "license": "manufacturer datasheet, values quoted for reference"
      }
    },
    {
      "benchmark": "max_service_temp",
      "label": "Service temperature of HexPly 8552 composites",
      "value": 121,
      "bound": "exact",
      "unit": "°C",
      "scope": "material",
      "conditions": {
        "unit_in_source": "250 °F",
        "basis": "stated service limit of the matrix system"
      },
      "method": "Service limit printed in a manufacturer datasheet, converted from 250 °F",
      "status": "ground",
      "source": "hexcel-8552",
      "where": "Features list, first bullet",
      "source_detail": {
        "title": "HexPly 8552 mid-toughened, high strength, damage-resistant, structural epoxy matrix, Product Data Sheet",
        "id": "Hexcel Corporation, Copyright 2020 (file uploaded 2026)",
        "url": "https://www.hexcel.com/wp-content/uploads/2026/01/HexPly_8552_us_DataSheet-1.pdf",
        "year": 2020,
        "kind": "datasheet",
        "license": "manufacturer datasheet, values quoted for reference"
      }
    },
    {
      "benchmark": "ultimate_tensile_strength",
      "label": "Tensile strength at 0 degrees, IM7/8552 unidirectional",
      "value": 2724,
      "bound": "exact",
      "unit": "MPa",
      "scope": "material",
      "conditions": {
        "fibre": "IM7",
        "matrix": "HexPly 8552",
        "layup": "unidirectional, 0 degrees",
        "temperature": "77 F (25 C)",
        "state": "dry",
        "unit_in_source": "395 ksi"
      },
      "method": "Typical value printed in a manufacturer datasheet (mechanical properties table), converted from 395 ksi (factor 6.894757)",
      "status": "ground",
      "source": "hexcel-8552",
      "where": "Mechanical Properties table, row 0 degrees Tensile strength, ksi, 77 Dry, IM7 column",
      "source_detail": {
        "title": "HexPly 8552 mid-toughened, high strength, damage-resistant, structural epoxy matrix, Product Data Sheet",
        "id": "Hexcel Corporation, Copyright 2020 (file uploaded 2026)",
        "url": "https://www.hexcel.com/wp-content/uploads/2026/01/HexPly_8552_us_DataSheet-1.pdf",
        "year": 2020,
        "kind": "datasheet",
        "license": "manufacturer datasheet, values quoted for reference"
      }
    },
    {
      "benchmark": "elastic_modulus",
      "label": "Tensile modulus at 0 degrees, IM7/8552 unidirectional",
      "value": 164,
      "bound": "exact",
      "unit": "GPa",
      "scope": "material",
      "conditions": {
        "fibre": "IM7",
        "matrix": "HexPly 8552",
        "layup": "unidirectional, 0 degrees",
        "temperature": "77 F (25 C)",
        "state": "dry",
        "unit_in_source": "23.8 msi"
      },
      "method": "Typical value printed in a manufacturer datasheet, converted from 23.8 msi (factor 6.894757)",
      "status": "ground",
      "source": "hexcel-8552",
      "where": "Mechanical Properties table, row 0 degrees Tensile modulus, msi, 77 Dry, IM7 column",
      "source_detail": {
        "title": "HexPly 8552 mid-toughened, high strength, damage-resistant, structural epoxy matrix, Product Data Sheet",
        "id": "Hexcel Corporation, Copyright 2020 (file uploaded 2026)",
        "url": "https://www.hexcel.com/wp-content/uploads/2026/01/HexPly_8552_us_DataSheet-1.pdf",
        "year": 2020,
        "kind": "datasheet",
        "license": "manufacturer datasheet, values quoted for reference"
      }
    },
    {
      "benchmark": "ultimate_tensile_strength",
      "label": "Tensile strength at 90 degrees, IM7/8552 unidirectional",
      "value": 64,
      "bound": "exact",
      "unit": "MPa",
      "scope": "material",
      "conditions": {
        "fibre": "IM7",
        "matrix": "HexPly 8552",
        "layup": "unidirectional, 90 degrees",
        "temperature": "77 F (25 C)",
        "state": "dry",
        "unit_in_source": "9.3 ksi"
      },
      "method": "Typical value printed in a manufacturer datasheet, converted from 9.3 ksi (factor 6.894757)",
      "status": "ground",
      "source": "hexcel-8552",
      "where": "Mechanical Properties table, row 90 degrees Tensile strength, ksi, 77 Dry, IM7 column",
      "source_detail": {
        "title": "HexPly 8552 mid-toughened, high strength, damage-resistant, structural epoxy matrix, Product Data Sheet",
        "id": "Hexcel Corporation, Copyright 2020 (file uploaded 2026)",
        "url": "https://www.hexcel.com/wp-content/uploads/2026/01/HexPly_8552_us_DataSheet-1.pdf",
        "year": 2020,
        "kind": "datasheet",
        "license": "manufacturer datasheet, values quoted for reference"
      }
    },
    {
      "benchmark": "elastic_modulus",
      "label": "Tensile modulus at 90 degrees, IM7/8552 unidirectional",
      "value": 11.7,
      "bound": "exact",
      "unit": "GPa",
      "scope": "material",
      "conditions": {
        "fibre": "IM7",
        "matrix": "HexPly 8552",
        "layup": "unidirectional, 90 degrees",
        "temperature": "77 F (25 C)",
        "state": "dry",
        "unit_in_source": "1.70 msi"
      },
      "method": "Typical value printed in a manufacturer datasheet, converted from 1.70 msi (factor 6.894757)",
      "status": "ground",
      "source": "hexcel-8552",
      "where": "Mechanical Properties table, row 90 degrees Tensile modulus, msi, 77 Dry, IM7 column",
      "source_detail": {
        "title": "HexPly 8552 mid-toughened, high strength, damage-resistant, structural epoxy matrix, Product Data Sheet",
        "id": "Hexcel Corporation, Copyright 2020 (file uploaded 2026)",
        "url": "https://www.hexcel.com/wp-content/uploads/2026/01/HexPly_8552_us_DataSheet-1.pdf",
        "year": 2020,
        "kind": "datasheet",
        "license": "manufacturer datasheet, values quoted for reference"
      }
    },
    {
      "benchmark": "ultimate_tensile_strength",
      "label": "Tensile strength, quasi-isotropic 25/50/25 laminate, IM7/8552",
      "value": 717,
      "bound": "exact",
      "unit": "MPa",
      "scope": "material",
      "conditions": {
        "fibre": "IM7",
        "matrix": "HexPly 8552",
        "layup": "quasi-isotropic 25/50/25",
        "temperature": "77 F (25 C)",
        "state": "dry",
        "unit_in_source": "104 ksi"
      },
      "method": "Typical value printed in a manufacturer datasheet, converted from 104 ksi (factor 6.894757)",
      "status": "ground",
      "source": "hexcel-8552",
      "where": "Mechanical Properties table, Quasi-Isotropic 25/50/25 block, row Tensile strength, IM7 column",
      "source_detail": {
        "title": "HexPly 8552 mid-toughened, high strength, damage-resistant, structural epoxy matrix, Product Data Sheet",
        "id": "Hexcel Corporation, Copyright 2020 (file uploaded 2026)",
        "url": "https://www.hexcel.com/wp-content/uploads/2026/01/HexPly_8552_us_DataSheet-1.pdf",
        "year": 2020,
        "kind": "datasheet",
        "license": "manufacturer datasheet, values quoted for reference"
      }
    },
    {
      "benchmark": "ultimate_tensile_strength",
      "label": "Tensile strength, T700S carbon fibre (single fibre)",
      "value": 4900,
      "bound": "exact",
      "unit": "MPa",
      "scope": "material",
      "conditions": {
        "fibre": "T700S, standard modulus, 12k and 24k tows",
        "layup": "not applicable (fibre property)",
        "temperature": "room temperature (not stated)",
        "unit_in_source": "500 kgf/mm2"
      },
      "method": "Nominal value printed in a manufacturer fibre data sheet (test method TY-QA-002)",
      "status": "ground",
      "source": "toray-t700s",
      "where": "Fibre properties table, row Tensile Strength, Nominal value",
      "source_detail": {
        "title": "Torayca T700S Carbon Fiber Data Sheet",
        "id": "Toray Carbon Fibers Europe, test methods TY-QA-002, TY-QA-003",
        "url": "https://toray-cfe.com/wp-content/uploads/2025/02/Torayca-T700S-Technical-Data-Sheet.pdf",
        "year": 2025,
        "kind": "datasheet",
        "license": "manufacturer datasheet, values quoted for reference"
      }
    },
    {
      "benchmark": "elastic_modulus",
      "label": "Tensile modulus, T700S carbon fibre",
      "value": 230,
      "bound": "exact",
      "unit": "GPa",
      "scope": "material",
      "conditions": {
        "fibre": "T700S",
        "layup": "not applicable (fibre property)",
        "unit_in_source": "23.5 kgf/mm2 x 10^3"
      },
      "method": "Nominal value printed in a manufacturer fibre data sheet (test method TY-QA-002)",
      "status": "ground",
      "source": "toray-t700s",
      "where": "Fibre properties table, row Tensile Modulus, Nominal value",
      "source_detail": {
        "title": "Torayca T700S Carbon Fiber Data Sheet",
        "id": "Toray Carbon Fibers Europe, test methods TY-QA-002, TY-QA-003",
        "url": "https://toray-cfe.com/wp-content/uploads/2025/02/Torayca-T700S-Technical-Data-Sheet.pdf",
        "year": 2025,
        "kind": "datasheet",
        "license": "manufacturer datasheet, values quoted for reference"
      }
    },
    {
      "benchmark": "density",
      "label": "Density, T700S carbon fibre",
      "value": 1.8,
      "bound": "exact",
      "unit": "g/cm3",
      "scope": "material",
      "conditions": {
        "fibre": "T700S",
        "temperature": "not stated"
      },
      "method": "Nominal value printed in a manufacturer fibre data sheet (test method TY-QA-003)",
      "status": "ground",
      "source": "toray-t700s",
      "where": "Fibre properties table, row Density",
      "source_detail": {
        "title": "Torayca T700S Carbon Fiber Data Sheet",
        "id": "Toray Carbon Fibers Europe, test methods TY-QA-002, TY-QA-003",
        "url": "https://toray-cfe.com/wp-content/uploads/2025/02/Torayca-T700S-Technical-Data-Sheet.pdf",
        "year": 2025,
        "kind": "datasheet",
        "license": "manufacturer datasheet, values quoted for reference"
      }
    },
    {
      "benchmark": "ultimate_tensile_strength",
      "label": "Tensile strength, T700S in a Toray 2500 epoxy composite",
      "value": 2550,
      "bound": "exact",
      "unit": "MPa",
      "scope": "material",
      "conditions": {
        "fibre": "T700S",
        "matrix": "Toray 2500, cure 120 C",
        "layup": "not stated in the datasheet",
        "fibre_volume": "60 % (normalized)",
        "temperature": "room temperature",
        "unit_in_source": "260 kgf/mm2"
      },
      "method": "Nominal value printed in a manufacturer composite-property table",
      "status": "ground",
      "source": "toray-t700s",
      "where": "Composite properties table, row Tensile Strength, footnote \"Toray 2500 - 120 C resin system, normalized to 60 % fiber volume\"",
      "source_detail": {
        "title": "Torayca T700S Carbon Fiber Data Sheet",
        "id": "Toray Carbon Fibers Europe, test methods TY-QA-002, TY-QA-003",
        "url": "https://toray-cfe.com/wp-content/uploads/2025/02/Torayca-T700S-Technical-Data-Sheet.pdf",
        "year": 2025,
        "kind": "datasheet",
        "license": "manufacturer datasheet, values quoted for reference"
      }
    },
    {
      "benchmark": "elastic_modulus",
      "label": "Tensile modulus, T700S in a Toray 2500 epoxy composite",
      "value": 135,
      "bound": "exact",
      "unit": "GPa",
      "scope": "material",
      "conditions": {
        "fibre": "T700S",
        "matrix": "Toray 2500, cure 120 C",
        "layup": "not stated in the datasheet",
        "fibre_volume": "60 % (normalized)",
        "temperature": "room temperature"
      },
      "method": "Nominal value printed in a manufacturer composite-property table",
      "status": "ground",
      "source": "toray-t700s",
      "where": "Composite properties table, row Tensile Modulus, footnote as above",
      "source_detail": {
        "title": "Torayca T700S Carbon Fiber Data Sheet",
        "id": "Toray Carbon Fibers Europe, test methods TY-QA-002, TY-QA-003",
        "url": "https://toray-cfe.com/wp-content/uploads/2025/02/Torayca-T700S-Technical-Data-Sheet.pdf",
        "year": 2025,
        "kind": "datasheet",
        "license": "manufacturer datasheet, values quoted for reference"
      }
    },
    {
      "benchmark": "moisture_absorption",
      "label": "Water uptake of adhesive-bonded T800H/3900-2 composite joints after ageing",
      "value": 0.75,
      "bound": "exact",
      "unit": "%",
      "scope": "material",
      "conditions": {
        "form": "single lap-shear specimens bonded from T800H/3900-2 prepreg panels",
        "ageing": "71 C and 85 % relative humidity",
        "duration": "360 days",
        "control": "stored at about 20 % relative humidity, little to no weight change"
      },
      "method": "Weight gain printed in the text after 360 days of ageing; mass measured on removal from the chamber. This is a bonded joint, not a laminate, so it is not a laminate saturation value.",
      "status": "ground",
      "source": "palmieri-2013",
      "where": "Results, paragraph on the aged lap-shear specimens after 360 days",
      "source_detail": {
        "title": "Supersonic retropulsion surface preparation of carbon fiber reinforced epoxy composites for adhesive bonding",
        "id": "F. L. Palmieri, M. A. Belcher, C. J. Wohl, K. Y. Blohowiak, J. W. Connell, NASA Langley and Boeing",
        "url": "https://ntrs.nasa.gov/citations/20130013699",
        "year": 2013,
        "kind": "paper",
        "license": "NASA NTRS public document"
      }
    },
    {
      "benchmark": "cte",
      "label": "Coefficient of thermal expansion, graphite-epoxy coupons, layup 0/30/90/-30",
      "value": 0.18,
      "bound": "exact",
      "unit": "ppm/K",
      "scope": "material",
      "conditions": {
        "form": "graphite-epoxy coupons, specimen set P45 987",
        "layup": "[0, 30, 90, -30] as printed in the report text (garbled in the extracted text)",
        "temperature": "not stated in the table",
        "unit_in_source": "10-6/C",
        "matrix": "not named in the report table"
      },
      "method": "Average of six coupon results printed in Table 3 of the report. The text says a correction factor of 0.9 ppm/C is added to raw laser-dilatometer readings to give the final result; the table is read here as the final value.",
      "status": "ground",
      "source": "nasa-tm104637",
      "where": "Table 3 (continued), P45 987 coupons, Average CTE row",
      "source_detail": {
        "title": "NASA Technical Memorandum 104637: Hygrothermal Properties of Composites",
        "id": "NASA TM 104637, P. Arsenovic, Goddard Space Flight Center, June 1996",
        "url": "https://ntrs.nasa.gov/citations/19960041513",
        "year": 1996,
        "kind": "report",
        "license": "NASA NTRS public document"
      }
    },
    {
      "benchmark": "total_mass_loss",
      "label": "Total mass loss in vacuum, AS-4/1908 epoxy/graphite laminate",
      "value": 0.11,
      "bound": "exact",
      "unit": "%",
      "scope": "material",
      "conditions": {
        "sample": "laminate, ID GSC10245, manufacturer HER",
        "cure": "2H (as printed in the database)",
        "test": "total mass loss in vacuum, per the NASA outgassing database"
      },
      "method": "Value read from the NASA outgassing database. The CSV prints no unit row, so percent of initial mass is assumed (the ASTM E595 convention used in NASA TM 104637). Not a value for the HexPly 8552 or T700S systems.",
      "status": "ground",
      "source": "nasa-outgassing-db",
      "where": "Row LAMINATE AS-4/1908 EPOXY/GRAPHITE (GSC10245), column TML",
      "source_detail": {
        "title": "NASA outgassing database (legacy Outgassing_Db CSV)",
        "id": "NASA data.nasa.gov, legacy Outgassing_Db",
        "url": "https://data.nasa.gov/docs/legacy/Outgassing_Db/Outgassing_Db_rows.csv",
        "kind": "database",
        "license": "NASA open data"
      }
    },
    {
      "benchmark": "total_mass_loss",
      "label": "Total mass loss in vacuum, CYCOM 985-T300 graphite/epoxy",
      "value": 0.57,
      "bound": "exact",
      "unit": "%",
      "scope": "material",
      "conditions": {
        "sample": "structural, ID GSC12224, manufacturer ACC",
        "cure": "1H (as printed in the database)",
        "test": "total mass loss in vacuum, per the NASA outgassing database"
      },
      "method": "Value read from the NASA outgassing database. No unit row in the CSV; percent assumed. Different resin system from HexPly 8552.",
      "status": "ground",
      "source": "nasa-outgassing-db",
      "where": "Row CYCOM 985-T300 GRAPHITE/EPOXY (GSC12224), column TML",
      "source_detail": {
        "title": "NASA outgassing database (legacy Outgassing_Db CSV)",
        "id": "NASA data.nasa.gov, legacy Outgassing_Db",
        "url": "https://data.nasa.gov/docs/legacy/Outgassing_Db/Outgassing_Db_rows.csv",
        "kind": "database",
        "license": "NASA open data"
      }
    },
    {
      "benchmark": "total_mass_loss",
      "label": "Total mass loss in vacuum, carbon fibre epoxy laminate T300/M76",
      "value": 0.6,
      "bound": "exact",
      "unit": "%",
      "scope": "material",
      "conditions": {
        "sample": "laminate, ID GSC28291, manufacturer HEC",
        "cure": "4H (as printed in the database)",
        "test": "total mass loss in vacuum, per the NASA outgassing database"
      },
      "method": "Value read from the NASA outgassing database. No unit row in the CSV; percent assumed. Different resin system from HexPly 8552.",
      "status": "ground",
      "source": "nasa-outgassing-db",
      "where": "Row CARBON FIBER EPOXY LAMINATE T300/M76 (GSC28291), column TML",
      "source_detail": {
        "title": "NASA outgassing database (legacy Outgassing_Db CSV)",
        "id": "NASA data.nasa.gov, legacy Outgassing_Db",
        "url": "https://data.nasa.gov/docs/legacy/Outgassing_Db/Outgassing_Db_rows.csv",
        "kind": "database",
        "license": "NASA open data"
      }
    }
  ],
  "corrosion": [
    {
      "environment": "Aluminium 7075 coupled to CFRP in 3.5 wt% NaCl",
      "headline": "Coupling aluminium to CFRP drives galvanic corrosion of the aluminium; the aluminium acts as the anode.",
      "effect": "In the coupled test the Al 7075 served as the anode, with accelerated dissolution at the interface. The paper says galvanic corrosion at the joint interfaces accelerates adhesive failure and strength damage.",
      "rating": "severe",
      "conditions": {
        "electrolyte": "3.5 wt% NaCl",
        "couple": "Al 7075 in contact with CFRP",
        "test": "galvanic coupling for 120 min, galvanic current density recorded"
      },
      "source": "sci-rep-2022-galvanic",
      "where": "Abstract; Results, galvanic current density and Fig. 1"
    },
    {
      "environment": "Al 7075 with plasma electrolytic oxidation (PEO) coating, coupled to CFRP in 3.5 wt% NaCl",
      "headline": "A PEO coating cut the galvanic current density by about 90 % over 120 min.",
      "effect": "The PEO-600 and PEO-700 coatings reduced galvanic current density by about 90 % against the uncoated Al-alloy/CFRP coupling and about 88 % against thin film sulphuric acid anodizing, averaged over 120 min. The paper calls this a promising protection for practical use; it is a laboratory coupon test.",
      "rating": "low",
      "conditions": {
        "electrolyte": "3.5 wt% NaCl",
        "method": "galvanic current density over 120 min"
      },
      "source": "sci-rep-2022-galvanic",
      "where": "Results text on galvanic current density after 120 min"
    },
    {
      "environment": "Hot, wet ageing of bonded CFRP joints at 71 C and 85 % relative humidity",
      "headline": "Bonded T800H/3900-2 joints gained about 0.75 % water and lost about 27 % of their apparent shear strength in 360 days.",
      "effect": "Control specimens showed little or no weight change. Aged apparent shear strength was 27.0 MPa against 36.6 MPa for controls. Failures stayed mostly cohesive.",
      "rating": "moderate",
      "conditions": {
        "temperature": "71 C",
        "humidity": "85 % relative humidity",
        "duration": "360 days",
        "specimen": "single lap-shear bonded joints, not laminates"
      },
      "source": "palmieri-2013",
      "where": "Results, aged lap-shear specimens after 360 days"
    },
    {
      "environment": "Moisture at elevated temperature in epoxy laminates",
      "headline": "Absorbed water softens the epoxy and lowers its glass transition temperature.",
      "effect": "The report says absorbed water softens epoxy resins, causes them to swell and lowers their glass transition temperature. No numeric shift for the HexPly 8552 resin was read in this run.",
      "rating": "moderate",
      "conditions": {
        "basis": "qualitative statement from a graphite/epoxy study with 0 % and 1 % moisture test conditions"
      },
      "source": "nasa-cr187229",
      "where": "Introduction, paragraph on absorbed moisture"
    }
  ],
  "risks": {
    "hazards": [
      {
        "text": "PubChem aggregates ECHA notifications for bisphenol A diglycidyl ether (BADGE), a common epoxy resin monomer. Skin irritation (H315), allergic skin reaction (H317) and serious eye irritation (H319) are each reported in more than 99.9 % of hazard-reporting notifications; H411 (toxic to aquatic life with long lasting effects) appears in 50.9 %. The HexPly 8552 formulation is not published, so this applies to the monomer, not to the cured laminate.",
        "ghs": [
          "H315: Causes skin irritation",
          "H317: May cause an allergic skin reaction",
          "H319: Causes serious eye irritation",
          "H411: Toxic to aquatic life with long lasting effects"
        ],
        "source": "pubchem-badge",
        "where": "GHS Classification, aggregated reports for CID 2286"
      },
      {
        "text": "The carbon fibre safety data sheet says inhalation of dust may cause irritation of the respiratory system and dust can cause eye irritation. Carcinogenicity, reproductive toxicity and sensitisation are listed as not classified. Dust from cutting, sanding or machining cured CFRP is the practical concern.",
        "ghs": [],
        "source": "rave-cf-sds",
        "where": "Section 8.2 (exposure controls) and Section 11 (symptoms, if inhaled and if in eyes)"
      }
    ],
    "failure_risks": [
      {
        "mode": "Moisture-driven loss of properties at elevated temperature",
        "consequence": "Absorbed moisture gives two effects: reversible plasticization of the epoxy matrix, and permanent degradation from microcracking in the matrix. The report says the permanent part cannot be predicted straightforwardly for composites.",
        "source": "nasa-otell-1978",
        "where": "Introduction, two modes of property degradation"
      },
      {
        "mode": "Bonded joint strength loss in hot, wet ageing",
        "consequence": "After 360 days at 71 C and 85 % relative humidity, apparent shear strength fell from 36.6 MPa to 27.0 MPa, about 27 %, with nearly all failures still cohesive in the composite.",
        "source": "palmieri-2013",
        "where": "Results, aged lap-shear specimens after 360 days"
      },
      {
        "mode": "Loading across the fibres",
        "consequence": "Unidirectional IM7/8552 gives 64 MPa at 90 degrees, against 2724 MPa along the fibres. The datasheet gives both values, so layup choice decides how much of the fibre strength a part can use.",
        "source": "hexcel-8552",
        "where": "Mechanical Properties table, 90 degree rows"
      }
    ],
    "side_effects": [
      {
        "text": "Epoxy composites release volatiles in vacuum. Database total mass loss for graphite/epoxy laminates ranges from 0.11 % to 0.6 % in the rows read here, with the total dominated by outgassing rather than erosion. These are other resin systems, not HexPly 8552.",
        "source": "nasa-outgassing-db",
        "where": "Carbon fibre and graphite epoxy laminate rows, column TML"
      }
    ],
    "handling": [
      {
        "text": "Keep prepreg at -18 C in a sealed moisture-proof bag; shelf life is 12 months from manufacture.",
        "source": "hexcel-8552",
        "where": "Prepreg Storage Life section"
      },
      {
        "text": "Operators should wear clean, impervious gloves when handling the resin and fibre.",
        "source": "hexcel-8552",
        "where": "Handling and Safety Precautions"
      }
    ],
    "mitigations": [
      {
        "text": "Standard surface preparation (grit blasting, manual abrasion, peel ply) can lack precision and reproducibility. The authors propose laser ablation of the composite surface resin as a precise, reproducible preparation before bonding.",
        "source": "palmieri-2013",
        "where": "Abstract"
      }
    ]
  },
  "uses": [
    {
      "application": "structures",
      "device": "Space launcher structures",
      "example": "Hexcel lists HexPly 8552 for space launchers, with space and defense aircraft structures among its applications.",
      "source": "hexcel-8552",
      "where": "Applications list at the top of the Product Data Sheet (Space Launchers; Space and Defense)"
    },
    {
      "application": "structures",
      "device": "Primary and secondary aircraft structures",
      "example": "The HexPly 8552 Product Data Sheet lists primary and secondary aircraft structures among its commercial aerospace applications.",
      "source": "hexcel-8552",
      "where": "Applications list at the top of the Product Data Sheet (Commercial Aerospace)"
    },
    {
      "application": "optics-and-cameras",
      "device": "Prototype optical bench of graphite-epoxy",
      "example": "NASA Goddard used a laser dilatometer to measure the CTE of graphite-epoxy structures, which allowed loading and thermal expansion tests on a prototype optical bench.",
      "source": "nasa-tm104637",
      "where": "Section I, summary"
    },
    {
      "application": "structures",
      "device": "Al-alloy/CFRP joint systems",
      "example": "Al-alloy/CFRP joint systems offer lightweight structure, fatigue behaviour and impact resistance, and are widely used in aerospace; galvanic corrosion at the aluminium interface is the main challenge.",
      "source": "sci-rep-2022-galvanic",
      "where": "Introduction"
    }
  ],
  "supply": [
    {
      "subject": "Carbon fibre (PAN-based), manufacturing sites for the Toray T700S grade",
      "abundance": "Not applicable: synthetic fibre made from a polymer precursor; no crustal abundance applies",
      "producers": [],
      "critical_lists": [],
      "substitutes": [],
      "source": "toray-t700s",
      "where": "Introduction paragraph of the Torayca T700S data sheet"
    }
  ],
  "media": [],
  "documents": [
    {
      "title": "HexPly 8552 Product Data Sheet (Hexcel)",
      "type": "datasheet",
      "url": "https://www.hexcel.com/wp-content/uploads/2026/01/HexPly_8552_us_DataSheet-1.pdf",
      "year": 2020
    },
    {
      "title": "Torayca T700S Carbon Fiber Data Sheet (Toray)",
      "type": "datasheet",
      "url": "https://toray-cfe.com/wp-content/uploads/2025/02/Torayca-T700S-Technical-Data-Sheet.pdf",
      "year": 2025
    },
    {
      "title": "NASA TM 104637: Hygrothermal Properties of Composites",
      "type": "report",
      "url": "https://ntrs.nasa.gov/citations/19960041513",
      "year": 1996
    },
    {
      "title": "NASA CR-187229: Environmental and Strain Rate Effects on Graphite/Epoxy Composites",
      "type": "report",
      "url": "https://ntrs.nasa.gov/citations/19920011242",
      "year": 1991
    },
    {
      "title": "NTRS 19790009882: Synthesis of Improved Moisture Resistant Polymers (final report)",
      "type": "report",
      "url": "https://ntrs.nasa.gov/citations/19790009882",
      "year": 1978
    },
    {
      "title": "Palmieri et al.: Supersonic retropulsion surface preparation of carbon fiber reinforced epoxy composites for adhesive bonding",
      "type": "paper",
      "url": "https://ntrs.nasa.gov/citations/20130013699",
      "year": 2013
    },
    {
      "title": "NASA outgassing database (legacy Outgassing_Db CSV)",
      "type": "database",
      "url": "https://data.nasa.gov/docs/legacy/Outgassing_Db/Outgassing_Db_rows.csv",
      "year": 2026
    },
    {
      "title": "Galvanic corrosion protection of Al-alloy in contact with CFRP through plasma electrolytic oxidation (Scientific Reports)",
      "type": "paper",
      "url": "https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8927304/",
      "year": 2022
    },
    {
      "title": "PubChem: Bisphenol A diglycidyl ether (CID 2286), GHS classification summary",
      "type": "database",
      "url": "https://pubchem.ncbi.nlm.nih.gov/compound/2286",
      "year": 2026
    },
    {
      "title": "Rave Scientific safety data sheet, carbon fibers SDS00170CC1016 v4.0",
      "type": "sds",
      "url": "https://ravescientific.com/images/pdf/SDS00170CC1016-01_Carbon_Fibre.pdf",
      "year": 2022
    }
  ],
  "gaps": [
    "Supply shares by country for PAN-based carbon fibre: no readable source found. Search results were market-research blogs with conflicting figures, so none were used.",
    "Laminate density and fibre volume fraction for the HexPly 8552 IM7 prepreg: not extracted; the datasheet density row is for neat resin.",
    "Outgassing of HexPly 8552 or T700S specifically: the NASA database has no row for these systems. The rows used are other epoxy and graphite/epoxy systems.",
    "NASA outgassing database CSV has no unit row: percent is assumed for TML values.",
    "Atomic oxygen erosion of CFRP: no readable source with a number. A search snippet gave 0.42 % mass loss for a quasi-isotropic laminate in LEO, but the paper was not read, so it is not used.",
    "UV ageing of CFRP epoxy: no readable source found.",
    "Thermal cycling and microcracking in orbit: the sources read describe permanent microcracking qualitatively; no thermal-cycling number was read.",
    "Water uptake of a HexPly 8552 or CFRP laminate at saturation: not read. The 0.75 % value is for bonded joints aged 360 days; the 1996 NASA moisture-absorption curves are shown only as figures in the text.",
    "Galvanic corrosion of CFRP with aluminium in a marine or seawater test: no source found; the 3.5 wt% NaCl test is a laboratory coupon.",
    "Outgassing and total mass loss are not in the property canon; total_mass_loss is a snake_case name used here.",
    "Critical-mineral status of PAN precursor and acrylonitrile: not read.",
    "The Toray 2500 composite row (T700S) has no stated layup in the datasheet.",
    "Laminate CTE for the HexPly 8552 system: not found. The 0.18 ppm/K value is for graphite-epoxy coupons with a different layup and resin not named in the table."
  ],
  "story": {
    "why": "Carbon-fibre reinforced epoxy combines high stiffness and strength with low density. Unidirectional IM7/8552 laminate reaches 164 GPa along the fibres and 2724 MPa at 0 degrees, and the T700S fibre itself is rated at 4900 MPa and 230 GPa with a density of 1.8 g/cm3. The matrix sets the working limits: the neat resin density is 1.3 g/cm3 and the service limit is 121 C.",
    "uses": [
      {
        "where": "Launcher and spacecraft structures",
        "line": "Hexcel lists space launchers and space and defense aircraft structures among typical uses of HexPly 8552."
      }
    ],
    "can_do": [
      {
        "label": "Property",
        "line": "A quasi-isotropic 25/50/25 IM7/8552 laminate gives 717 MPa tensile strength. Hexcel lists it among typical uses for space launchers and primary aircraft structures.",
        "scope": "material"
      }
    ],
    "compare": "The Toray composite row gives 2550 MPa for T700S in a Toray 2500 epoxy, against 4900 MPa for the fibre alone, so the matrix and test conditions take off about half the fibre strength in that test.",
    "compare_rows": [
      {
        "label": "Strength along the fibres",
        "benchmark": "ultimate_tensile_strength",
        "scope": "material"
      },
      {
        "label": "Stiffness along the fibres",
        "benchmark": "elastic_modulus",
        "scope": "material"
      },
      {
        "label": "Density",
        "benchmark": "density",
        "scope": "material"
      }
    ],
    "handling": [
      "Keep prepreg frozen at -18 C in a sealed bag until lay-up; shelf life is 12 months from manufacture.",
      "Wear clean, impervious gloves when handling resin and fibre.",
      "Cutting, sanding or machining cured CFRP makes dust. Use ventilation, avoid dust formation, and dampen or vacuum spills.",
      "Check the SDS for the product you handle: the epoxy monomer carries skin and sensitisation hazards (H317 in the PubChem record)."
    ],
    "good_for": [
      "Stiff, light structures that must carry load along known directions."
    ],
    "watch_out": [
      "Check the 90 degree strength and the 121 C service limit before you set the layup and environment."
    ],
    "verdict": "Strong and stiff along the fibres; weak across them and limited by the epoxy at about 121 C.",
    "recipe": {
      "line": "Carbon fibre is made by spinning a precursor polymer, mostly polyacrylonitrile (PAN), into filaments, oxidising them in air and carbonising them to drive off non-carbon atoms. The fibre is impregnated with a toughened amine-cured epoxy; the HexPly 8552 prepreg is cured at 350 F.",
      "parts": [
        {
          "name": "Carbon fibre (PAN-based)",
          "role": "Carries the load along its length and gives the stiffness and strength of the laminate."
        },
        {
          "name": "Toughened amine-cured epoxy resin",
          "role": "Holds the fibres in place, transfers load between them and sets the service temperature."
        }
      ]
    },
    "risk_groups": [
      {
        "title": "For people",
        "lead": "The sources read here describe the composite and its resin as a structural material, not as a hazard to people in use.",
        "points": [
          {
            "label": "Handling prepreg",
            "line": "Hexcel recommends that operators wear clean, impervious gloves to reduce skin contact with the prepreg. Shelf life is 12 months at -18 C in a sealed bag."
          }
        ],
        "level": 1,
        "verdict": "No hazard data read"
      },
      {
        "title": "If it fails",
        "lead": "The 90 degree strength is the weak direction. Failures found in the sources are about loading across the fibres.",
        "points": [
          {
            "label": "Loading across the fibres",
            "line": "Unidirectional IM7/8552 gives 64 MPa at 90 degrees, against 2724 MPa along the fibres. The datasheet gives both values, so layup choice decides how much of the fibre strength a part can use."
          },
          {
            "label": "Heat",
            "line": "The HexPly 8552 matrix is rated to a service temperature of 121 C (250 F). Above that limit the datasheet gives no data."
          }
        ]
      },
      {
        "title": "Handling and storage",
        "points": [
          {
            "label": "Keep it cold until use",
            "line": "Tack life is 10 days at room temperature and out life is 30 days. Keep the prepreg frozen until it is laid up."
          }
        ]
      }
    ]
  },
  "updated": "2026-10-19",
  "review": {
    "status": "draft",
    "method": "assistant",
    "checked_values": 17,
    "unreachable": 1,
    "caveats": 6,
    "note": "Deepen pass on 2026-10-19: five new properties read from NASA TM 104637 (CTE), the NASA outgassing database (three TML rows) and Palmieri et al. 2013 (water uptake), each checked against fetched text. Unreachable: atomic oxygen and UV numbers for CFRP. Caveats: the 0.18 ppm/K CTE is for graphite-epoxy coupons, not HexPly 8552; TML rows are other resin systems; the 0.75 % water uptake is for bonded joints."
  },
  "sources": {
    "hexcel-8552": {
      "title": "HexPly 8552 mid-toughened, high strength, damage-resistant, structural epoxy matrix, Product Data Sheet",
      "id": "Hexcel Corporation, Copyright 2020 (file uploaded 2026)",
      "url": "https://www.hexcel.com/wp-content/uploads/2026/01/HexPly_8552_us_DataSheet-1.pdf",
      "year": 2020,
      "kind": "datasheet",
      "license": "manufacturer datasheet, values quoted for reference"
    },
    "toray-t700s": {
      "title": "Torayca T700S Carbon Fiber Data Sheet",
      "id": "Toray Carbon Fibers Europe, test methods TY-QA-002, TY-QA-003",
      "url": "https://toray-cfe.com/wp-content/uploads/2025/02/Torayca-T700S-Technical-Data-Sheet.pdf",
      "year": 2025,
      "kind": "datasheet",
      "license": "manufacturer datasheet, values quoted for reference"
    },
    "nasa-tm104637": {
      "title": "NASA Technical Memorandum 104637: Hygrothermal Properties of Composites",
      "id": "NASA TM 104637, P. Arsenovic, Goddard Space Flight Center, June 1996",
      "url": "https://ntrs.nasa.gov/citations/19960041513",
      "year": 1996,
      "kind": "report",
      "license": "NASA NTRS public document"
    },
    "nasa-cr187229": {
      "title": "NASA Contractor Report 187229: Environmental and Strain Rate Effects on Graphite/Epoxy Composites",
      "id": "NASA CR-187229, K. Peimandis, Northwestern University, October 1991",
      "url": "https://ntrs.nasa.gov/citations/19920011242",
      "year": 1991,
      "kind": "report",
      "license": "NASA NTRS public document"
    },
    "nasa-otell-1978": {
      "title": "Synthesis of Improved Moisture Resistant Polymers: final report",
      "id": "NTRS 19790009882, M. K. Otell, TRW Defense and Space Systems Group, NASA contract NAS3-21011",
      "url": "https://ntrs.nasa.gov/citations/19790009882",
      "year": 1978,
      "kind": "report",
      "license": "NASA NTRS public document"
    },
    "palmieri-2013": {
      "title": "Supersonic retropulsion surface preparation of carbon fiber reinforced epoxy composites for adhesive bonding",
      "id": "F. L. Palmieri, M. A. Belcher, C. J. Wohl, K. Y. Blohowiak, J. W. Connell, NASA Langley and Boeing",
      "url": "https://ntrs.nasa.gov/citations/20130013699",
      "year": 2013,
      "kind": "paper",
      "license": "NASA NTRS public document"
    },
    "nasa-outgassing-db": {
      "title": "NASA outgassing database (legacy Outgassing_Db CSV)",
      "id": "NASA data.nasa.gov, legacy Outgassing_Db",
      "url": "https://data.nasa.gov/docs/legacy/Outgassing_Db/Outgassing_Db_rows.csv",
      "kind": "database",
      "license": "NASA open data"
    },
    "sci-rep-2022-galvanic": {
      "title": "Galvanic corrosion protection of Al-alloy in contact with carbon fibre reinforced polymer through plasma electrolytic oxidation treatment",
      "id": "Scientific Reports 12, 4532 (2022)",
      "url": "https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8927304/",
      "year": 2022,
      "kind": "paper",
      "license": "CC-BY 4.0 (open access)"
    },
    "pubchem-badge": {
      "title": "PubChem: Bisphenol A diglycidyl ether (CID 2286), GHS classification summary",
      "id": "PubChem, National Center for Biotechnology Information",
      "url": "https://pubchem.ncbi.nlm.nih.gov/compound/2286",
      "year": 2026,
      "kind": "database",
      "license": "PubChem public data"
    },
    "rave-cf-sds": {
      "title": "Safety data sheet: High purity carbon fibers in carbon fiber threads, document SDS00170CC1016 version 4.0",
      "id": "Rave Scientific, Regulation (EC) No 1907/2006 Art. 31, dated October 5th 2022",
      "url": "https://ravescientific.com/images/pdf/SDS00170CC1016-01_Carbon_Fibre.pdf",
      "year": 2022,
      "kind": "datasheet",
      "license": "supplier safety data sheet, quoted for reference"
    },
    "wiki-carbon-fibre": {
      "title": "Carbon fiber (Wikipedia article, Carbon fibers)",
      "id": "Wikipedia, article Carbon fibers",
      "url": "https://en.wikipedia.org/wiki/Carbon_fibers",
      "year": 2026,
      "kind": "web",
      "license": "CC BY-SA 4.0"
    }
  },
  "license": "CC-BY-4.0",
  "url": "https://spacemushroom.com/profiles/cfrp/"
}