Phenolic resin (phenol-formaldehyde; Bakelite and phenolic laminates) PF
Phenol polymer with formaldehyde (CAS 9003-35-4): a cross-linked network made by condensing phenol with formaldehyde · CAS 9003-35-4
Also known as Bakelite
Phenolic resin is a thermoset made by condensing phenol with formaldehyde.
Evidence level
2 of 5
Lab-measured
- 0Predicted only. No one has made it, or no measurement exists.
- 1Calculated. Only calculated or predicted values from sources.
- 2Lab-measured. Measured properties with their conditions stated.
- 3Space-relevant tests. Measured in conditions relevant to space, such as vacuum or atomic oxygen.
- 4Ground-qualified. Qualified for an application on the ground.
- 5Flown or field-proven. Flight or field results exist.
Char yield
49%
Cured resin density
1.21 g/cc
Continuous service
125 °C
Recipe, share of the weight
- not statedPhenol
- not statedFormaldehyde
Best for
Char-forming ablators and laminates for gears and bearings, where a hard, machinable thermoset is needed (NEMA LE cotton phenolic: 13 ksi lengthwise tensile)
Weakest at
Low char yield and low decomposition onset compared with polyimide and cyanate ester, and a lower glass transition than cyanate ester and polybenzoxazine (NASA)
Risk at a glance
- People None found. Uncured resin corrosive and a sensitiser
- If it fails Moderate. Thermal decomposition of the cured resin
- Corrosion Moderate. The heritage cured phenolic starts to decompose at 375 °C and leaves 49% char.
Quick facts: PF
| Property | Value | Basis |
|---|---|---|
| Density | 1.21 to 1.32 g/cm³ | 3 sourced values across conditions |
| Tensile strength | 62 to 93.1 MPa | 3 sourced values across conditions |
| Maximum service temperature | 121 to 125 °C | 2 sourced values across conditions |
What is the density of Phenolic resin (PF)?
Phenolic resin (PF) has a density of 1.21 to 1.32 g/cm³. The range covers 3 sourced values across the tempers, forms and test conditions the sources report; room-temperature values are used where a source states a temperature.
What is the tensile strength of Phenolic resin (PF)?
Phenolic resin (PF) has a tensile strength of 62 to 93.1 MPa. The range covers 3 sourced values across the tempers, forms and test conditions the sources report; room-temperature values are used where a source states a temperature.
What is the maximum service temperature of Phenolic resin (PF)?
Phenolic resin (PF) has a maximum service temperature of 121 to 125 °C. The range covers 2 sourced values across the tempers, forms and test conditions the sources report; room-temperature values are used where a source states a temperature.
What is Phenolic resin (PF) used for?
Uses recorded in the sources include Ablative heatshield, PICA carbon phenolic; Phenolic-nylon charring ablator test material (1960s); Gears, pinions and bearings.
Why it exists
Phenolic resins are used where a char-forming, heat-resistant thermoset is needed. PICA, a carbon fibre felt impregnated with phenolic resin, has flown as a heat shield on Stardust and is used on Mars Science Laboratory and SpaceX Dragon. Phenolic laminates are used for gears, pinions and bearings because they are tough and machinable. NASA's comparison shows the heritage resin's weak points, low char yield and a low decomposition onset.
Where it's used
Heat shields
PICA, a phenolic-impregnated carbon ablator, was the Stardust heatshield and is the forebody heatshield for Mars Science Laboratory and SpaceX Dragon.
Gears and bearings
NEMA LE cotton phenolic laminate is printed as suited to gears, pinions and bearings, with a 90 MPa lengthwise tensile strength.
Recipe
Phenol polymer with formaldehyde (CAS 9003-35-4): a cross-linked network made by condensing phenol with formaldehyde
Phenol and formaldehyde react in a condensation reaction, with an acid or base catalyst, to give a soluble intermediate that hardens under heat and pressure into an insoluble, hard resin. Phenol is made mainly by the cumene process, the dominant industrial route.
| Ingredient | Share of the weight | What it does |
|---|---|---|
| Phenol | not stated | The aromatic monomer; its hydroxyl-bearing ring joins to formaldehyde at the ring positions to build the network. |
| Formaldehyde | not stated | The cross-linking monomer that links phenol rings together. |
Weight shares are as printed in the sources.
What it can do
Char yield
49%
The heritage resin SC1008 left 49% char at 10 C/min in inert gas.
Cured resin density
1.21 g/cc
The cured SC1008 resin has a density of 1.21 g/cc, as printed in the NASA resin table.
Continuous service
125 °C
The NEMA LE laminate has a printed maximum operating temperature of 125 °C.
How it compares
Phenolic is the heritage ablative resin. NASA's 2019 resin study compared it with cyanate ester, polybenzoxazine, polyimidazole and polyimide. Phenolic had a lower char yield and a lower decomposition onset than polyimide and cyanate ester in the same table, and a lower glass transition than cyanate ester and polybenzoxazine. The laminate grades are cotton based; their tensile values are typical, not specification values.
The same measurements for each material, so you can compare them. Each row names the key condition under the value; the full conditions and methods are in the numbered notes under Technical details. Other materials are shown beside it; each was measured under its own conditions, so open its page before comparing closely. Compare every grade in the family.
| Measurement | PF | EP |
|---|---|---|
| Physical and electrical | ||
| Density, cured phenolic resin SC1008 (heritage ablative resin) | 1.21 g/cc1 | 1.115 g/cm³ |
| Density, LE-675 cotton fabric phenolic laminate | 1.32 g/cc4 | 1.115 g/cm³ |
| Specific gravity, NEMA LE cotton phenolic laminate | 1.34 -5 | 1.115 g/cm³ |
| Temperature behavior | ||
| Decomposition temperature, cured phenolic resin SC1008 | 375 °C2 | no data |
| Other measurements | ||
| Char yield, cured phenolic resin SC1008 | 49 %3 | no data |
| Flash point, uncured phenolic resin product ACE PGY | 100 °C6 | no data |
| Maximum operating temperature, NEMA LE laminate | 125 °C7 | no data |
| Continuous heat resistance, LE-675 laminate (printed in Fahrenheit) | 250 °F8 | no data |
| Tensile strength lengthwise, NEMA LE laminate | 90 MPa9 | 69 MPa |
| Tensile strength crosswise, NEMA LE laminate | 62 MPa10 | 69 MPa |
| Tensile strength lengthwise, LE-675 laminate | 13500 psi11 | 69 MPa |
| Flexural strength lengthwise, NEMA LE laminate | 152 MPa12 | no data |
| Flexural strength crosswise, NEMA LE laminate | 110 MPa13 | no data |
| Shear strength, NEMA LE laminate | 93 MPa14 | 41 MPa |
| Moisture absorption, NEMA LE laminateMoisture absorption row, ASTM D-570, as printed | 1.9 % | no data |
| Dielectric strength, NEMA LE laminate, Condition A | 625 V/mil15 | no data |
Why choose it, and why not
Good for
- Char-forming heat shields, where the char carries heat away on re-entry.
- Machinable laminate gears, pinions and bearings made from cotton phenolic grades.
Watch out for
- Low char yield and a low decomposition onset compared with polyimide and cyanate ester.
- Lower glass transition than cyanate ester and polybenzoxazine, so the matrix softens earlier.
- PICA billets vary in density, which changes thermal sizing and lot acceptance.
Phenolic resin is a proven, cheap heat-shield and laminate resin with heritage flight use, but NASA's own comparison shows low char yield and a low glass transition. Newer resins are being developed to beat it.
Technical details
For scientists and researchers. Everything above comes from the record below: every number with its method, its conditions and its source.
Other names and standards
The same grade under other systems, as datasheets and standards print them. Each code was checked against the page it comes from.
| System | Codes |
|---|---|
| Trade name | Bakelite |
Notes
The method, full conditions and any caveat for the numbered rows above.
| # | Measurement | Method | Conditions | Caveat |
|---|---|---|---|---|
| 1 | Density, cured phenolic resin SC1008 (heritage ablative resin) | Density column of the resin table in the NASA resin characterization (ERC Inc. and NASA Ames), as printed | resin SC1008 heritage phenolic, cured neat resin without a reinforcing matrixbasis compression-test specimens of cured resin | — |
| 2 | Decomposition temperature, cured phenolic resin SC1008 | Thermogravimetric analysis, decomposition temperature column, as printed | resin SC1008 heritage phenolic, cured neat resinatmosphere inert gasheating rate 10 C/min | — |
| 3 | Char yield, cured phenolic resin SC1008 | Thermogravimetric analysis, char yield column, as printed; non-canonical benchmark name | resin SC1008 heritage phenolic, cured neat resinatmosphere inert gasheating rate 10 C/min | — |
| 4 | Density, LE-675 cotton fabric phenolic laminate | Density row of the Phenolite grade table, as printed (GM/CC) | grade LE-675 (Phenolite, cotton fabric based laminate) | — |
| 5 | Specific gravity, NEMA LE cotton phenolic laminate | Specific gravity printed in the typical values table; test method not printed for this row | grade NEMA LE (natural or black), cotton based phenolic laminate | — |
| 6 | Flash point, uncured phenolic resin product ACE PGY | Physical properties section of the safety data sheet, as printed with a greater-than-or-equal sign | product ACE PGY uncured phenolic resin (liquid)basis printed as at least 100 °C (lower limit) | — |
| 7 | Maximum operating temperature, NEMA LE laminate | Typical values table, Maximum Operating Temperature row; the degree sign is missing in the PDF text layer and reads as 0C there | grade NEMA LEbasis maximum operating temperature, typical value, no time limit printed | — |
| 8 | Continuous heat resistance, LE-675 laminate (printed in Fahrenheit) | Grade table row Heat Resistance, Farenheit, Continuous, as printed | grade LE-675basis heat resistance, continuous, as printed in Fahrenheit | — |
| 9 | Tensile strength lengthwise, NEMA LE laminate | Tensile strength row, ASTM D-638, printed as 13 (90) ksi (MPa); the MPa figure is recorded | grade NEMA LE, 0.125 in thicknessdirection lengthwise | — |
| 10 | Tensile strength crosswise, NEMA LE laminate | Tensile strength row, ASTM D-638, printed as 9 (62) ksi (MPa); the MPa figure is recorded | grade NEMA LE, 0.125 in thicknessdirection crosswise | — |
| 11 | Tensile strength lengthwise, LE-675 laminate | Grade table row Tensile Strength, PSI, Lengthwise, as printed (13,500 PSI) | grade LE-675direction lengthwise | — |
| 12 | Flexural strength lengthwise, NEMA LE laminate | Flexural strength row, printed as 22 (152) ksi (MPa); the test method is printed as ASTM D-695 on that row | grade NEMA LEdirection lengthwise | — |
| 13 | Flexural strength crosswise, NEMA LE laminate | Flexural strength row, printed as 16 (110) ksi (MPa); the test method is printed as ASTM D-695 on that row | grade NEMA LEdirection crosswise | — |
| 14 | Shear strength, NEMA LE laminate | Shear strength row, ASTM D-732, printed as 13.5 (93) ksi (MPa); the MPa figure is recorded | grade NEMA LE | — |
| 15 | Dielectric strength, NEMA LE laminate, Condition A | Dielectric strength row, Condition A column, as printed in V/mil | grade NEMA LEthickness 0.062 incondition A (as printed) | — |
Corrosion and compatibility
What happens when it meets other materials and environments.
| Environment | Concern | What happens |
|---|---|---|
| Thermal decomposition in inert gas, heated at 10 C/min (thermogravimetric analysis) | moderate | The heritage cured phenolic starts to decompose at 375 °C and leaves 49% char.1 |
| Continuous service temperature (NEMA LE laminate, typical value) | not rated | The datasheet prints a maximum operating temperature of 125 °C and no ageing data.2 |
| Humidity, ASTM D-570 moisture absorption (NEMA LE laminate) | low | The laminate absorbs 1.9% moisture under the ASTM D-570 test.3 |
| # | Environment | Details | Test conditions |
|---|---|---|---|
| 1 | Thermal decomposition in inert gas, heated at 10 C/min (thermogravimetric analysis) | Decomposition begins at 375 °C and the char yield is 49%, lower than polyimide and cyanate ester in the same table. NASA lists low char yield and low decomposition onset as phenolic weaknesses. | atmosphere inert gasheating rate 10 C/min |
| 2 | Continuous service temperature (NEMA LE laminate, typical value) | The sheet gives a typical maximum operating temperature only. No time at temperature or property retention is printed, so the rating is unknown. | grade NEMA LE |
| 3 | Humidity, ASTM D-570 moisture absorption (NEMA LE laminate) | Moisture absorption is printed as 1.9%. The same sheet prints 3.5% for the NEMA C grade, so the LE grade absorbs less moisture than C. | grade NEMA LEtest ASTM D-570 |
Risks and side effects
Hazards to people, what happens when a cell overheats, and how the material is handled and stored.
For people
The uncured ACE PGY resin is classed in the Mersen SDS as corrosive to skin and eyes and as a skin sensitiser.
- Skin and eyes
- Causes severe skin burns and eye damage (H314) and may cause an allergic skin reaction (H317), per the SDS.
In heating
Heritage phenolic gives 49% char in inert gas but starts to decompose at 375 degC, with a lower glass transition than the newer resins NASA tested.
- Char
- The heritage resin SC1008 leaves 49% char at 10 C/min in inert gas.
Test details
The original wording and numbers from the sources, for readers who want them.
Failure risks
| Failure | Trigger and consequence |
|---|---|
| Thermal decomposition of the cured resinmoderate severity | Heating above the onset in inert gas at 10 C/minMass loss starts at 375 °C; the heritage resin leaves 49% char. |
| Softening as the matrix nears its glass transitionmoderate severity | Heating toward the glass transition temperature of the resinNASA reports that phenolic has a lower glass transition than cyanate ester and polybenzoxazine, so the matrix softens sooner and mechanical properties drop. The Tg value itself was not read. |
| Lot-to-lot density variation in carbon-phenolic ablator billetslow severity | Manufacturing spread in PICA billetsNASA notes significant density variation in PICA billets, which matters for lot acceptance and for thermal sizing. |
| Moisture uptake in servicelow severity | Humid air or immersion (ASTM D-570 test)The NEMA LE laminate absorbs 1.9% moisture by mass under the printed test. |
Handling and storage
- Wear gloves and eye protection; the SDS classes the uncured resin as causing severe skin burns and eye damage and as a skin sensitiser.
- During processing, vapours of phenol and benzaldehyde may be released; use ventilation, and an approved respirator when exposed to vapours from heated material, as the SDS advises.
Documents
Datasheets, safety data sheets, papers and standards you can open.
Full record
The complete spore, as stored. Free to reuse under CC-BY-4.0. Images keep the licence shown with each one.
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spore: profile
id: phenolic-resin
spore_version: 0.2
family: engineering-polymers
name: Phenolic resin (phenol-formaldehyde; Bakelite and phenolic laminates)
abbreviation: PF
role: thermosetting resin for ablative heat shields, laminates and moulded parts
category: polymers
type: epoxies-and-resins
summary: |
Phenolic resin is a thermoset made by condensing phenol with formaldehyde. Cured, it forms a hard, insoluble network. Bakelite was the first commercial form, developed in 1907 and patented in 1909. NASA's PICA heat shield is a carbon fibre felt impregnated with phenolic resin; it was the Stardust heatshield and is the forebody heatshield for Mars Science Laboratory and the SpaceX Dragon. In a 2019 NASA comparison, the heritage phenolic resin SC1008 left 49% char in inert gas but decomposed from 375 degC, with a lower char yield and a lower glass transition than the newer resins tested.
best_for: 'Char-forming ablators and laminates for gears and bearings, where a hard, machinable thermoset is needed (NEMA LE cotton phenolic: 13 ksi lengthwise tensile)'
weakest_at: Low char yield and low decomposition onset compared with polyimide and cyanate ester, and a lower glass transition than cyanate ester and polybenzoxazine (NASA)
identity:
formula: 'Phenol polymer with formaldehyde (CAS 9003-35-4): a cross-linked network made by condensing phenol with formaldehyde'
cas: 9003-35-4
source: mersen-sds
where: 'Composition table (ingredients), first row: Phenol polymer with formaldehyde, CAS-No. 9003-35-4'
designations:
- system: Trade name
code: Bakelite
source: wiki-bakelite
where: Article title and first paragraph
tags:
environments:
- re-entry
stresses:
- high-heat-flux
- humidity
applications:
- heat-shields
- mechanisms
- electronics-and-chips
properties:
- benchmark: density
label: Density, cured phenolic resin SC1008 (heritage ablative resin)
value: 1.21
unit: g/cc
scope: material
conditions:
resin: SC1008 heritage phenolic, cured neat resin without a reinforcing matrix
basis: compression-test specimens of cured resin
method: Density column of the resin table in the NASA resin characterization (ERC Inc. and NASA Ames), as printed
status: ground
source: boghozian2019
where: Resin density table, Phenolic resin row (slide on compression-test samples)
- benchmark: decomposition_temperature
label: Decomposition temperature, cured phenolic resin SC1008
value: 375
unit: °C
scope: material
conditions:
resin: SC1008 heritage phenolic, cured neat resin
atmosphere: inert gas
heating_rate: 10 C/min
method: Thermogravimetric analysis, decomposition temperature column, as printed
status: ground
source: boghozian2019
where: TGA results table, SC1008 row (Decomposition temperature column)
- benchmark: char_yield
label: Char yield, cured phenolic resin SC1008
value: 49
unit: '%'
scope: material
conditions:
resin: SC1008 heritage phenolic, cured neat resin
atmosphere: inert gas
heating_rate: 10 C/min
method: Thermogravimetric analysis, char yield column, as printed; non-canonical benchmark name
status: ground
source: boghozian2019
where: TGA results table, SC1008 row (Char Yield column)
- benchmark: density
label: Density, LE-675 cotton fabric phenolic laminate
value: 1.32
unit: g/cc
scope: material
conditions:
grade: LE-675 (Phenolite, cotton fabric based laminate)
method: Density row of the Phenolite grade table, as printed (GM/CC)
status: ground
source: midwest-phenolite
where: Grade table, row Density, LE-675 column
- benchmark: density
label: Specific gravity, NEMA LE cotton phenolic laminate
value: 1.34
unit: '-'
scope: material
conditions:
grade: NEMA LE (natural or black), cotton based phenolic laminate
method: Specific gravity printed in the typical values table; test method not printed for this row
status: ground
source: gund-datasheet
where: Typical values table, Specific Gravity row, NEMA LE column
- benchmark: flash_point
label: Flash point, uncured phenolic resin product ACE PGY
value: 100
unit: °C
scope: material
conditions:
product: ACE PGY uncured phenolic resin (liquid)
basis: printed as at least 100 degC (lower limit)
method: Physical properties section of the safety data sheet, as printed with a greater-than-or-equal sign
status: ground
source: mersen-sds
where: Physical and chemical properties section, Flash point row
- benchmark: max_service_temp
label: Maximum operating temperature, NEMA LE laminate
value: 125
unit: °C
scope: material
conditions:
grade: NEMA LE
basis: maximum operating temperature, typical value, no time limit printed
method: Typical values table, Maximum Operating Temperature row; the degree sign is missing in the PDF text layer and reads as 0C there
status: ground
source: gund-datasheet
where: Typical values table, Maximum Operating Temperature row, NEMA LE column
- benchmark: max_service_temp
label: Continuous heat resistance, LE-675 laminate (printed in Fahrenheit)
value: 250
unit: °F
scope: material
conditions:
grade: LE-675
basis: heat resistance, continuous, as printed in Fahrenheit
method: Grade table row Heat Resistance, Farenheit, Continuous, as printed
status: ground
source: midwest-phenolite
where: Grade table, Heat Resistance row, LE-675 column
- benchmark: ultimate_tensile_strength
label: Tensile strength lengthwise, NEMA LE laminate
value: 90
unit: MPa
scope: material
conditions:
grade: NEMA LE, 0.125 in thickness
direction: lengthwise
method: Tensile strength row, ASTM D-638, printed as 13 (90) ksi (MPa); the MPa figure is recorded
status: ground
source: gund-datasheet
where: Key characteristics table, Tensile Strength Lengthwise row, NEMA LE column
- benchmark: ultimate_tensile_strength
label: Tensile strength crosswise, NEMA LE laminate
value: 62
unit: MPa
scope: material
conditions:
grade: NEMA LE, 0.125 in thickness
direction: crosswise
method: Tensile strength row, ASTM D-638, printed as 9 (62) ksi (MPa); the MPa figure is recorded
status: ground
source: gund-datasheet
where: Key characteristics table, Tensile Strength Crosswise row, NEMA LE column
- benchmark: ultimate_tensile_strength
label: Tensile strength lengthwise, LE-675 laminate
value: 13500
unit: psi
scope: material
conditions:
grade: LE-675
direction: lengthwise
method: Grade table row Tensile Strength, PSI, Lengthwise, as printed (13,500 PSI)
status: ground
source: midwest-phenolite
where: Grade table, Tensile Strength Lengthwise row, LE-675 column
- benchmark: flexural_strength
label: Flexural strength lengthwise, NEMA LE laminate
value: 152
unit: MPa
scope: material
conditions:
grade: NEMA LE
direction: lengthwise
method: Flexural strength row, printed as 22 (152) ksi (MPa); the test method is printed as ASTM D-695 on that row
status: ground
source: gund-datasheet
where: Key characteristics table, Flexural Strength Lengthwise row, NEMA LE column
- benchmark: flexural_strength
label: Flexural strength crosswise, NEMA LE laminate
value: 110
unit: MPa
scope: material
conditions:
grade: NEMA LE
direction: crosswise
method: Flexural strength row, printed as 16 (110) ksi (MPa); the test method is printed as ASTM D-695 on that row
status: ground
source: gund-datasheet
where: Key characteristics table, Flexural Strength Crosswise row, NEMA LE column
- benchmark: shear_strength
label: Shear strength, NEMA LE laminate
value: 93
unit: MPa
scope: material
conditions:
grade: NEMA LE
method: Shear strength row, ASTM D-732, printed as 13.5 (93) ksi (MPa); the MPa figure is recorded
status: ground
source: gund-datasheet
where: Key characteristics table, Shear Strength row, NEMA LE column
- benchmark: moisture_absorption
label: Moisture absorption, NEMA LE laminate
value: 1.9
unit: '%'
scope: material
conditions:
grade: NEMA LE
test: ASTM D-570 (test exposure not printed on the sheet)
method: Moisture absorption row, ASTM D-570, as printed
status: ground
source: gund-datasheet
where: Key characteristics table, Moisture Absorption row, NEMA LE column
- benchmark: dielectric_strength
label: Dielectric strength, NEMA LE laminate, Condition A
value: 625
unit: V/mil
scope: material
conditions:
grade: NEMA LE
thickness: 0.062 in
condition: A (as printed)
method: Dielectric strength row, Condition A column, as printed in V/mil
status: ground
source: gund-datasheet
where: Key characteristics table, Dielectric Strength (0.062 in) row, Condition A, NEMA LE column
corrosion:
- environment: Thermal decomposition in inert gas, heated at 10 C/min (thermogravimetric analysis)
headline: The heritage cured phenolic starts to decompose at 375 °C and leaves 49% char.
effect: Decomposition begins at 375 °C and the char yield is 49%, lower than polyimide and cyanate ester in the same table. NASA lists low char yield and low decomposition onset as phenolic weaknesses.
rating: moderate
conditions:
atmosphere: inert gas
heating_rate: 10 C/min
source: boghozian2019
where: TGA results table; Objective and Motivation slide
- environment: Continuous service temperature (NEMA LE laminate, typical value)
headline: The datasheet prints a maximum operating temperature of 125 °C and no ageing data.
effect: The sheet gives a typical maximum operating temperature only. No time at temperature or property retention is printed, so the rating is unknown.
rating: unknown
conditions:
grade: NEMA LE
source: gund-datasheet
where: Typical values table, Maximum Operating Temperature row
- environment: Humidity, ASTM D-570 moisture absorption (NEMA LE laminate)
headline: The laminate absorbs 1.9% moisture under the ASTM D-570 test.
effect: Moisture absorption is printed as 1.9%. The same sheet prints 3.5% for the NEMA C grade, so the LE grade absorbs less moisture than C.
rating: low
conditions:
grade: NEMA LE
test: ASTM D-570
source: gund-datasheet
where: Key characteristics table, Moisture Absorption row
risks:
hazards:
- text: 'Mersen safety data sheet for the uncured ACE PGY phenolic resin: signal word Danger; causes severe skin burns and eye damage (H314), may cause an allergic skin reaction (H317) and is harmful if inhaled (H332).'
ghs:
- H314
- H317
- H332
source: mersen-sds
where: Hazard statements (CLP) block of the safety data sheet
- text: The same SDS also lists suspected genetic defects (H341), may cause cancer (H350), may damage fertility or the unborn child (H360), may cause organ damage on repeated exposure (H373) and harmful to aquatic life with long lasting effects (H412).
ghs:
- H341
- H350
- H360
- H373
- H412
source: mersen-sds
where: Hazard statements (CLP) block of the safety data sheet
failure_risks:
- mode: Thermal decomposition of the cured resin
trigger: Heating above the onset in inert gas at 10 C/min
consequence: Mass loss starts at 375 °C; the heritage resin leaves 49% char.
severity: moderate
source: boghozian2019
where: TGA results table, SC1008 row
- mode: Softening as the matrix nears its glass transition
trigger: Heating toward the glass transition temperature of the resin
consequence: NASA reports that phenolic has a lower glass transition than cyanate ester and polybenzoxazine, so the matrix softens sooner and mechanical properties drop. The Tg value itself was not read.
severity: moderate
source: boghozian2019
where: Glass transition slide, phenolic comparison
- mode: Lot-to-lot density variation in carbon-phenolic ablator billets
trigger: Manufacturing spread in PICA billets
consequence: NASA notes significant density variation in PICA billets, which matters for lot acceptance and for thermal sizing.
severity: low
source: ellerby2019
where: Slide titled PICA Billet Has Significant Variability in Density
- mode: Moisture uptake in service
trigger: Humid air or immersion (ASTM D-570 test)
consequence: The NEMA LE laminate absorbs 1.9% moisture by mass under the printed test.
severity: low
source: gund-datasheet
where: Key characteristics table, Moisture Absorption row
side_effects: []
handling:
- text: Wear gloves and eye protection; the SDS classes the uncured resin as causing severe skin burns and eye damage and as a skin sensitiser.
source: mersen-sds
where: Hazard statements (CLP) block; handling section
- text: During processing, vapours of phenol and benzaldehyde may be released; use ventilation, and an approved respirator when exposed to vapours from heated material, as the SDS advises.
source: mersen-sds
where: Additional hazards when processed; exposure controls section
mitigations: []
uses:
- application: heat-shields
device: Ablative heatshield, PICA carbon phenolic
example: PICA, a carbon fibre insulation impregnated with phenolic resin, was the Stardust heatshield and is the forebody heatshield for Mars Science Laboratory and the SpaceX Dragon.
source: milos-pica2009
where: Section I (Introduction)
- application: heat-shields
device: Phenolic-nylon charring ablator test material (1960s)
example: The high-density phenolic-nylon ablator in a 1965 NASA study was 50% by weight Union Carbide Bakelite BRP-5549 phenolic resin.
source: tnd2991-1965
where: Test materials, high-density phenolic-nylon description
- application: mechanisms
device: Gears, pinions and bearings
example: The Gund datasheet describes NEMA C, CE and LE cotton phenolic laminates as suited to gears, pinions and bearings.
source: gund-datasheet
where: Product description paragraph
- application: electronics-and-chips
device: Electrical insulating bushings
example: The earliest commercial electrical use of Bakelite was insulating bushings made in 1908 for the Weston Electrical Instrument Corporation.
source: wiki-bakelite
where: Main uses section
story:
recipe:
line: Phenol and formaldehyde react in a condensation reaction, with an acid or base catalyst, to give a soluble intermediate that hardens under heat and pressure into an insoluble, hard resin. Phenol is made mainly by the cumene process, the dominant industrial route.
parts:
- name: Phenol
role: The aromatic monomer; its hydroxyl-bearing ring joins to formaldehyde at the ring positions to build the network.
- name: Formaldehyde
role: The cross-linking monomer that links phenol rings together.
risk_groups:
- title: For people
level: 0
verdict: Uncured resin corrosive and a sensitiser
lead: The uncured ACE PGY resin is classed in the Mersen SDS as corrosive to skin and eyes and as a skin sensitiser.
points:
- label: Skin and eyes
line: Causes severe skin burns and eye damage (H314) and may cause an allergic skin reaction (H317), per the SDS.
- title: In heating
verdict: Chars well, softens and decomposes early
lead: Heritage phenolic gives 49% char in inert gas but starts to decompose at 375 degC, with a lower glass transition than the newer resins NASA tested.
points:
- label: Char
line: The heritage resin SC1008 leaves 49% char at 10 C/min in inert gas.
why: Phenolic resins are used where a char-forming, heat-resistant thermoset is needed. PICA, a carbon fibre felt impregnated with phenolic resin, has flown as a heat shield on Stardust and is used on Mars Science Laboratory and SpaceX Dragon. Phenolic laminates are used for gears, pinions and bearings because they are tough and machinable. NASA's comparison shows the heritage resin's weak points, low char yield and a low decomposition onset.
uses:
- where: Heat shields
line: PICA, a phenolic-impregnated carbon ablator, was the Stardust heatshield and is the forebody heatshield for Mars Science Laboratory and SpaceX Dragon.
- where: Gears and bearings
line: NEMA LE cotton phenolic laminate is printed as suited to gears, pinions and bearings, with a 90 MPa lengthwise tensile strength.
can_do:
- label: Char yield
value: 49%
line: The heritage resin SC1008 left 49% char at 10 C/min in inert gas.
- label: Cured resin density
value: 1.21 g/cc
line: The cured SC1008 resin has a density of 1.21 g/cc, as printed in the NASA resin table.
- label: Continuous service
value: 125 °C
line: The NEMA LE laminate has a printed maximum operating temperature of 125 °C.
compare: Phenolic is the heritage ablative resin. NASA's 2019 resin study compared it with cyanate ester, polybenzoxazine, polyimidazole and polyimide. Phenolic had a lower char yield and a lower decomposition onset than polyimide and cyanate ester in the same table, and a lower glass transition than cyanate ester and polybenzoxazine. The laminate grades are cotton based; their tensile values are typical, not specification values.
compare_rows:
- label: Density
benchmark: density
- label: Maximum service temperature
benchmark: max_service_temp
- label: Flexural strength
benchmark: flexural_strength
handling:
- Wear gloves and eye protection; the uncured resin is corrosive to skin and eyes and is a skin sensitiser.
- Process with ventilation; phenol and benzaldehyde vapours are released during processing.
good_for:
- Char-forming heat shields, where the char carries heat away on re-entry.
- Machinable laminate gears, pinions and bearings made from cotton phenolic grades.
watch_out:
- Low char yield and a low decomposition onset compared with polyimide and cyanate ester.
- Lower glass transition than cyanate ester and polybenzoxazine, so the matrix softens earlier.
- PICA billets vary in density, which changes thermal sizing and lot acceptance.
verdict: Phenolic resin is a proven, cheap heat-shield and laminate resin with heritage flight use, but NASA's own comparison shows low char yield and a low glass transition. Newer resins are being developed to beat it.
gaps:
- No glass transition temperature for the cured phenolic was read. The NASA resin slide gives a 260 degC value but does not tie it to a resin clearly, so no Tg is used.
- No UV, atomic oxygen or chemical resistance data for cured phenolic was read. The one ageing search returned no UV or hygrothermal study for cured phenolic.
- No thermal ageing data beyond the continuous service limit printed on the datasheet.
- 'No supply data: producer country shares for phenol and formaldehyde were not found in a source read in this run. The Wikipedia phenol article names the cumene process as dominant but gives no country shares.'
- Critical-mineral status was not checked; the feedstocks are petrochemical and no USGS or EU list entry was opened.
- The PubChem GHS summary for CAS 9003-35-4 could not be read (reCAPTCHA page). Hazards come from the Mersen SDS for one uncured resin product only.
- Hazard data apply to the uncured ACE PGY resin, not to a cured laminate or the NEMA grades.
- PICA numeric properties (density, thermal conductivity, heat capacity, char density) are not printed in the Milos and Chen paper, which withholds them under export control, and the 2019 NASA slides show only normalised plots. No numeric PICA or carbon-phenolic property was read.
- A Japanese carbon-phenolic density range appeared only in a search snippet and is not used.
- 'Non-canonical benchmark names in use: decomposition_temperature and char_yield are not in spores/property-canon.yaml.'
- 'Designations: NEMA LI-1 grade codes (C, CE, LE) and IEC 60893 codes (PFCC 201, 202, 204) do not fit the designation systems list, so they are not recorded.'
- No thermoset type exists in src/data/taxonomy.ts. The closest type, epoxies-and-resins, is used.
- The Gund datasheet prints the maximum operating temperature unit with the degree sign lost in the PDF text layer; 125 is read in degrees Celsius from the same row.
- The Midwest Composites page gives LE-675 lengthwise tensile as 13,500 PSI; an earlier search snippet gave 14,000, which is not used.
sources:
boghozian2019:
title: Characterization of New TPS Resins
id: NTRS 20190033961; T. Boghozian (ERC International), M. Stackpoole (NASA Ames), G. Gonzales (ERC International); NSMMS and CRASTE Joint Symposia, June 2019
url: https://ntrs.nasa.gov/citations/20190033961
year: 2019
kind: report
license: NASA NTRS public record
gund-datasheet:
title: NEMA C, CE, LE Phenolic Resin Cotton Cloth technical data sheet
id: The Gund Company, TCGR 03/2023
url: https://thegundcompany.com/wp-content/uploads/2025/12/NEMA-C-CE-LE-Phenolic-Resin-Cotton-Cloth-by-The-Gund-Co.pdf
year: 2023
kind: datasheet
license: manufacturer datasheet, cited
midwest-phenolite:
title: Phenolite cotton fabric based laminate grade specifications
id: Midwest Composites, cotspecs grade table (undated page)
url: https://midwestcomposites.clearlight.com/cotspecs.htm
kind: datasheet
license: manufacturer datasheet, cited
mersen-sds:
title: ACE PGY phenolic resin, safety data sheet (English)
id: Mersen, 2023
url: https://de.mersen.com/sites/default/files/files_imported/ace-pgy-phenolic-resin-english-2023.pdf
year: 2023
kind: datasheet
license: manufacturer SDS, cited
wiki-bakelite:
title: Bakelite
id: Wikipedia article, read 2026-10-26
url: https://en.wikipedia.org/wiki/Bakelite
kind: web
license: CC BY-SA 4.0
wiki-phenol:
title: Phenol
id: Wikipedia article, read 2026-10-26
url: https://en.wikipedia.org/wiki/Phenol
kind: web
license: CC BY-SA 4.0
milos-pica2009:
title: Ablation and Thermal Response Property Model Validation for Phenolic Impregnated Carbon Ablator
id: AIAA-2009-0262; F.S. Milos and Y.-K. Chen, NASA Ames, 47th AIAA Aerospace Sciences Meeting, January 2009; NTRS 20110012891
url: https://ntrs.nasa.gov/citations/20110012891
year: 2009
kind: paper
license: NASA NTRS public record
ellerby2019:
title: Thermal Properties - Do We Trust Them? Yes'ish (panel discussion slides)
id: Don Ellerby, NASA Ames; 30th Annual Thermal and Fluids Analysis Workshop, August 26, 2019; NTRS 20190030277
url: https://ntrs.nasa.gov/api/citations/20190030277/downloads/20190030277.pdf
year: 2019
kind: report
license: NASA NTRS public record
tnd2991-1965:
title: Thermophysical properties of six charring ablators from 140 to 700 K and two chars from 800 to 3000 K
id: NASA TN D-2991, 1965; NTRS 19650024901
url: https://ntrs.nasa.gov/citations/19650024901
year: 1965
kind: report
license: NASA NTRS public record
documents:
- type: sds
title: ACE PGY phenolic resin, safety data sheet (English)
url: https://de.mersen.com/sites/default/files/files_imported/ace-pgy-phenolic-resin-english-2023.pdf
- type: datasheet
title: NEMA C, CE, LE Phenolic Resin Cotton Cloth technical data sheet
url: https://thegundcompany.com/wp-content/uploads/2025/12/NEMA-C-CE-LE-Phenolic-Resin-Cotton-Cloth-by-The-Gund-Co.pdf
- type: report
title: Characterization of New TPS Resins
url: https://ntrs.nasa.gov/citations/20190033961
- type: paper
title: Ablation and Thermal Response Property Model Validation for Phenolic Impregnated Carbon Ablator
url: https://ntrs.nasa.gov/citations/20110012891
review:
status: draft
method: assistant
checked_values: 16
caveats: 9
note: Written by an AI assistant from pages and PDFs read in this run; 16 values, 9 sources. Tg, UV and atomic oxygen ageing, supply shares and PICA numeric properties were not found in a readable source.
updated: '2026-10-26'
license: CC-BY-4.0
References
Every number above carries a reference number. Click one to see the source and where in it the value comes from.
| # | Source | Type | Year | Used for |
|---|---|---|---|---|
| Characterization of New TPS Resins | report | 2019 | 6 values | |
| NEMA C, CE, LE Phenolic Resin Cotton Cloth technical data sheet | datasheet | 2023 | 13 values | |
| Phenolite cotton fabric based laminate grade specifications | datasheet | 3 values | ||
| ACE PGY phenolic resin, safety data sheet (English) | datasheet | 2023 | 6 values | |
| Bakelite | web | 1 value | ||
| Phenol | web | 0 values | ||
| Ablation and Thermal Response Property Model Validation for Phenolic Impregnated Carbon Ablator | paper | 2009 | 1 value | |
| Thermal Properties - Do We Trust Them? Yes'ish (panel discussion slides) | report | 2019 | 1 value | |
| Thermophysical properties of six charring ablators from 140 to 700 K and two chars from 800 to 3000 K | report | 1965 | 1 value |