spore: profile
id: pen
spore_version: 0.2
family: polyesters
name: Polyethylene naphthalate (PEN), biaxially oriented film and engineering resin
abbreviation: PEN
role: Polyester film for motor slot and phase insulation, and a higher-temperature alternative to PET film
category: polymers
type: polyesters
summary: |
  PEN is a polyester made from naphthalene-2,6-dicarboxylic acid (or its dimethyl ester) and ethylene glycol. It is the naphthalene analogue of PET, and Indorama describes its thermal, barrier and UV properties as improved over PET. Biaxially oriented PEN film, sold as Teonex, has a density of 1.36 g/cm3 and a tensile strength of 200 MPa. The electrical grade Teonex Q 51 lists a melting point of 269 °C (DSC) and a continuous working temperature of 160/180 °C under UL 746B. No atomic-oxygen flight value for PEN was found in the sources checked for this profile.
best_for: Thin, stiff, heat-tolerant electrical film, where PET runs out of temperature margin (motor slot insulation, flexible substrates)
weakest_at: 'Little published ageing data: no flight atomic-oxygen value and no quantitative humidity or UV result was found in the sources checked'
identity:
  formula: (C14H10O4)n, repeat unit C14H10O4 (poly(ethylene 2,6-naphthalate), from naphthalene-2,6-dicarboxylic acid and ethylene glycol)
  cas: 24968-11-4
  source: indorama-pen-spec
  where: Title line, CAS 24968-11-4 / 25853-85-4. Repeat-unit formula from the Wikipedia infobox (source wikipedia-pen, Properties section)
  designations:
    - system: Trade name
      code: Teonex
      source: synflex-q5100
      where: Title and footer, 'Teonex is a registered trademark of TOYOBO'
    - system: Trade name
      code: TN8050SC
      source: plabase-tn8050sc
      where: Grade name in the property table header
tags:
  environments: []
  stresses:
    - uv
    - hydrolysis
  applications:
    - electronics-and-chips
properties:
  - benchmark: density
    label: Density, biaxially oriented PEN film (Goodfellow data sheet)
    value: 1.36
    unit: g/cm3
    scope: material
    conditions:
      form: biax film
      note: film properties as printed on the PEN granule data sheet
    method: Value printed in the Physical Properties table of the Goodfellow data sheet
    status: ground
    source: goodfellow-pen-tds
    where: Physical Properties table, Density row
  - benchmark: density
    label: Density, PEN resin grade TN8050SC
    value: 1.33
    unit: g/cm3
    scope: material
    conditions:
      test: ISO 1183
      grade: TN8050SC
      note: processing form not stated on the page
    method: Value printed in the TN8050SC property table (ISO 1183)
    status: ground
    source: plabase-tn8050sc
    where: Basic section, Density row
  - benchmark: glass_transition_temperature
    label: Glass transition temperature (primary alpha relaxation), quenched PEN sheet
    value: 387
    unit: K
    scope: material
    conditions:
      method: modulated DSC at 2 K/min
      sample: PEN from molten Goodfellow pellets, quenched to a 0.5 mm sheet
      note: printed in kelvin; the importer converts to 114 degC
    method: Primary glass transition read from the Cp jump, printed as Tg=387 K; a secondary relaxation at about 305 K is not used here
    status: ground
    source: arxiv-pen-mdsc
    where: Results, text on the MDSC heat flow and reversing Cp (Fig. 3)
  - benchmark: melting_point
    label: Melting point, Teonex Q 51 electrical film
    value: 269
    unit: °C
    scope: material
    conditions:
      method: DSC
      product: Teonex Q 51 FI 14090 film
    method: Value printed in the technical data table of the Mueller-Ahlhorn data sheet
    status: ground
    source: mueller-q51-fi
    where: Technical data table, Melting temperature row
  - benchmark: melting_point
    label: Melting point range, PEN resin sales specification
    value: 262
    value_high: 275
    unit: °C
    scope: material
    conditions:
      method: DSC
      product: PEN pellets, sales specification
    method: Range printed in Table 1 of the Indorama sales specification
    status: ground
    source: indorama-pen-spec
    where: Table 1, Melting Point row
  - benchmark: ultimate_tensile_strength
    label: Tensile strength, biaxial PEN film (Goodfellow data sheet)
    value: 200
    unit: MPa
    scope: material
    conditions:
      form: biax film
      thickness: not stated
      test: not stated
    method: Value printed in the Mechanical Properties table
    status: ground
    source: goodfellow-pen-tds
    where: Mechanical Properties table, Tensile strength row
  - benchmark: ultimate_tensile_strength
    label: Tensile strength, Teonex Q5100 film 50 micron, longitudinal
    value: 290
    unit: MPa
    scope: material
    conditions:
      thickness: 50 micron
      direction: longitudinal
      form: biaxially oriented film
    method: Value printed in the Mechanical table of the SynFlex data sheet (updated 06/24)
    status: ground
    source: synflex-q5100
    where: Mechanical table, Tensile strength longitudinal row, 50 micron column
  - benchmark: ultimate_tensile_strength
    label: Tensile strength, Teonex Q5100 film 50 micron, transversal
    value: 300
    unit: MPa
    scope: material
    conditions:
      thickness: 50 micron
      direction: transversal
      form: biaxially oriented film
    method: Value printed in the same Mechanical table
    status: ground
    source: synflex-q5100
    where: Mechanical table, Tensile strength transversal row, 50 micron column
  - benchmark: elongation
    label: Elongation at break, biaxial PEN film (Goodfellow data sheet)
    value: 60
    unit: '%'
    scope: material
    conditions:
      form: biax film
    method: Value printed in the Mechanical Properties table
    status: ground
    source: goodfellow-pen-tds
    where: Mechanical Properties table, Elongation at break row
  - benchmark: elongation
    label: Elongation at break, Teonex Q5100 film 50 micron, longitudinal
    value: 120
    unit: '%'
    scope: material
    conditions:
      thickness: 50 micron
      direction: longitudinal
    method: Value printed in the Mechanical table of the SynFlex data sheet
    status: ground
    source: synflex-q5100
    where: Mechanical table, Elongation at break longitudinal row, 50 micron column
  - benchmark: elongation
    label: Tensile strain at break, PEN resin grade TN8050SC (ISO 527)
    value: 15
    unit: '%'
    scope: material
    conditions:
      test: ISO 527-1,2, 50 mm/min
      grade: TN8050SC
    method: Value printed in the TN8050SC property table
    status: ground
    source: plabase-tn8050sc
    where: Mechanical section, Tensile strain at break row
  - benchmark: elastic_modulus
    label: Tensile modulus, biaxial PEN film (Goodfellow data sheet)
    value: 5
    value_high: 5.5
    unit: GPa
    scope: material
    conditions:
      form: biax film
    method: Range printed in the Mechanical Properties table
    status: ground
    source: goodfellow-pen-tds
    where: Mechanical Properties table, Tensile modulus row
  - benchmark: elastic_modulus
    label: Tensile modulus, PEN resin grade TN8050SC (ISO 527)
    value: 2200
    unit: MPa
    scope: material
    conditions:
      test: ISO 527-1,2, 1 mm/min
      grade: TN8050SC
    method: Value printed in the TN8050SC property table
    status: ground
    source: plabase-tn8050sc
    where: Mechanical section, Tensile modulus row
  - benchmark: flexural_modulus
    label: Flexural modulus, PEN resin grade TN8050SC (ISO 178)
    value: 2250
    unit: MPa
    scope: material
    conditions:
      test: ISO 178, 2 mm/min
      grade: TN8050SC
    method: Value printed in the TN8050SC property table
    status: ground
    source: plabase-tn8050sc
    where: Mechanical section, Flexural modulus row
  - benchmark: flexural_strength
    label: Bending strength, PEN resin grade TN8050SC (ISO 178)
    value: 99
    unit: MPa
    scope: material
    conditions:
      test: ISO 178, 2 mm/min
      grade: TN8050SC
    method: Value printed in the TN8050SC property table
    status: ground
    source: plabase-tn8050sc
    where: Mechanical section, Bending strength row
  - benchmark: yield_strength
    label: Tensile yield stress, PEN resin grade TN8050SC (ISO 527)
    value: 80
    unit: MPa
    scope: material
    conditions:
      test: ISO 527-1,2, 50 mm/min
      grade: TN8050SC
    method: Value printed in the TN8050SC property table
    status: ground
    source: plabase-tn8050sc
    where: Mechanical section, Tensile yield stress row
  - benchmark: heat_deflection_temperature
    label: Deflection temperature under load at 1.80 MPa, PEN resin grade TN8050SC
    value: 91
    unit: °C
    scope: material
    conditions:
      test: ISO 75-1,2
      load: 1.80 MPa
      grade: TN8050SC
    method: Value printed in the TN8050SC property table
    status: ground
    source: plabase-tn8050sc
    where: Thermal section, Deflection temperature under load (1.80MPa) row
  - benchmark: heat_deflection_temperature
    label: Deflection temperature under load at 0.45 MPa, PEN resin grade TN8050SC
    value: 105
    unit: °C
    scope: material
    conditions:
      test: ISO 75-1,2
      load: 0.45 MPa
      grade: TN8050SC
    method: Value printed in the TN8050SC property table
    status: ground
    source: plabase-tn8050sc
    where: Thermal section, Deflection temperature under load (0.45MPa) row
  - benchmark: thermal_conductivity
    label: Thermal conductivity, biaxial PEN film at 23 °C
    value: 0.15
    unit: W m-1 K-1
    scope: material
    conditions:
      temperature: 23 °C
      form: biax film
    method: Value printed in the Thermal Properties table
    status: ground
    source: goodfellow-pen-tds
    where: Thermal Properties table, Thermal conductivity row
  - benchmark: cte
    label: Coefficient of thermal expansion, biaxial PEN film
    value: 20
    value_high: 21
    unit: x10-6 K-1
    scope: material
    conditions:
      form: biax film
    method: Range printed in the Thermal Properties table, printed as 20-21 x10^-6 K^-1
    status: ground
    source: goodfellow-pen-tds
    where: Thermal Properties table, Coefficient of thermal expansion row
  - benchmark: max_service_temp
    label: Upper working temperature, PEN film (Goodfellow data sheet)
    value: 155
    unit: °C
    scope: material
    conditions:
      basis: upper working temperature as printed
    method: Value printed in the Thermal Properties table
    status: ground
    source: goodfellow-pen-tds
    where: Thermal Properties table, Upper working temperature row
  - benchmark: max_service_temp
    label: Continuous working temperature, Teonex Q 51 electrical film (UL 746B)
    value: 160
    value_high: 180
    unit: °C
    scope: material
    conditions:
      standard: UL 746B
      note: printed as 160/180; the data sheet gives an electrical RTI of 180 °C and a mechanical RTI of 160 °C
    method: Range printed in the technical data table of the Mueller-Ahlhorn data sheet
    status: ground
    source: mueller-q51-fi
    where: Technical data table, Continuous working temperature row; Properties text on UL RTI
  - benchmark: dielectric_constant
    label: Dielectric constant, biaxial PEN film
    value: 3.2
    unit: '-'
    scope: material
    conditions:
      frequency: 10 kHz (printed as @10KHz under a 1 MHz heading)
    method: Value printed in the Electrical Properties table
    status: ground
    source: goodfellow-pen-tds
    where: Electrical Properties table, Dielectric constant row
  - benchmark: dielectric_strength
    label: Dielectric strength, biaxial PEN film
    value: 160
    unit: kV/mm
    scope: material
    conditions:
      thickness: 0.075 mm
    method: Value printed in the Electrical Properties table
    status: ground
    source: goodfellow-pen-tds
    where: Electrical Properties table, Dielectric strength row
  - benchmark: dielectric_strength
    label: Dielectric strength, Teonex Q 51 electrical film (JIS C-2318)
    value: 250
    unit: kV/mm
    scope: material
    conditions:
      test: JIS C-2318
      thickness: not stated on the data sheet
    method: Value printed in the technical data table
    status: ground
    source: mueller-q51-fi
    where: Technical data table, Dielectric strength row
  - benchmark: moisture_absorption
    label: Water absorption, biaxial PEN film
    value: 0.4
    unit: '%'
    scope: material
    conditions:
      form: biax film
    method: Value printed in the Physical Properties table
    status: ground
    source: goodfellow-pen-tds
    where: Physical Properties table, Water absorption row
  - benchmark: moisture_absorption
    label: Water absorption, Teonex Q 51 electrical film (TDF method)
    value: 0.3
    unit: '%'
    scope: material
    conditions:
      test: TDF method
      product: Teonex Q 51 FI 14090
    method: Value printed in the technical data table
    status: ground
    source: mueller-q51-fi
    where: Technical data table, Water absorption row
corrosion:
  - environment: Ultraviolet light
    headline: The Goodfellow data sheet rates UV resistance as Fair; no quantitative UV test was found.
    effect: The sales specification says PEN has better UV-penetration barrier properties than PET, but it gives no number. Weathering under sunlight is not quantified in the sources checked.
    rating: moderate
    conditions:
      test: qualitative rating, no unit given
    source: goodfellow-pen-tds
    where: Physical Properties table, Resistance to Ultra-violet row
  - environment: Hot humid conditions (hydrolysis and thermal ageing)
    headline: Ageing at 140 to 190 °C in dry and wet air and nitrogen degrades PEN to a different extent from PET.
    effect: The paper says PEN is thought to have increased thermal and hydrolytic resistance compared with PET, but few studies had examined PEN degradation. The abstract gives no numbers for the extent of loss; the full data were not readable.
    rating: moderate
    conditions:
      temperature: 140 to 190 °C
      atmospheres: dry nitrogen, dry air, wet nitrogen, wet air
    source: strath-ageing-2011
    where: Abstract
  - environment: Continuous heat in air
    headline: Continuous working temperature is 160/180 °C (UL 746B) for the electrical grade, and the upper working limit is 155 °C on the granule sheet.
    effect: The data sheets give service limits only. Above them the film is not rated, and no strength loss at higher temperature was found in the sources checked.
    rating: moderate
    conditions:
      standard: UL 746B
      film: Teonex Q 51
    source: mueller-q51-fi
    where: Technical data table, Continuous working temperature row
  - environment: Heat during processing (dimensional stability)
    headline: Shrinkage after 30 min at 150 °C is 0.4 % longitudinal, rising to 0.8 % at 200 °C, for 50 micron film.
    effect: Film shrinks when heated because it relaxes strain from manufacture. Shrinkage is small at 150 °C, and the 200 °C figure is about twice as large.
    rating: low
    conditions:
      thickness: 50 micron
      direction: longitudinal
      tests: 30 min at 150 °C; at 200 °C
    source: synflex-q5100
    where: Mechanical table, Shrinkage rows, 50 micron column
  - environment: Moisture uptake
    headline: Water absorption is 0.3 % to 0.4 % for the films.
    effect: Low uptake limits the water available for hydrolysis, but the ageing abstract still lists hydrolysis as a risk at elevated temperature.
    rating: low
    conditions:
      test: TDF method (Mueller), printed as water absorption (Goodfellow)
    source: goodfellow-pen-tds
    where: Physical Properties table, Water absorption row
  - environment: Chemical exposure
    headline: Good resistance to dilute acids, alcohols, alkalis, aromatic hydrocarbons, greases and oils, halogenated hydrocarbons and ketones.
    effect: Concentrated acids are rated Good to Poor. The ratings are qualitative and have no units.
    rating: low
    conditions:
      basis: qualitative chemical resistance table
    source: goodfellow-pen-tds
    where: Chemical Resistance table
risks:
  hazards:
    - text: 'Indorama sales specification: the product does not require any hazard warning on the label under OSHA criteria. The DOT product shipping name is not regulated, and the HS code is 3907.99.'
      ghs: []
      source: indorama-pen-spec
      where: Health and Safety Information; shipping paragraph
    - text: Goodfellow data sheet rates the film VTM-2 under UL 94 at 0.075 mm, a thin-material vertical burn class.
      ghs: []
      source: goodfellow-pen-tds
      where: Physical Properties table, Flammability row
  failure_risks:
    - mode: Hydrolytic and thermal ageing in hot, humid conditions
      trigger: Ageing at 140 to 190 °C in wet air or wet nitrogen
      consequence: The extent of degradation differs from PET, and the mechanism changes with temperature. The abstract gives no loss figures.
      severity: moderate
      source: strath-ageing-2011
      where: Abstract
    - mode: Shrinkage of the film when heated
      trigger: 30 min at 150 °C, or 200 °C
      consequence: 0.4 % shrinkage longitudinal at 150 °C and 0.8 % at 200 °C for 50 micron film.
      severity: low
      source: synflex-q5100
      where: Mechanical table, Shrinkage rows, 50 micron column
  side_effects: []
  handling:
    - text: Obtain the current safety data sheet for the grade before use. The Indorama sheet says a customer should consult the SDS before using any material.
      source: indorama-pen-spec
      where: Health and Safety Information
    - text: Pellets are shipped in 1000 kg polypropylene fabric bags or 100 kg fibre drums, and four drums can go on one pallet.
      source: indorama-pen-spec
      where: Shipping and Handling Information
  mitigations:
    - text: Specify the grade by its continuous working temperature. For Teonex Q 51 this is 160/180 °C (UL 746B), which is the rated figure rather than the 155 °C upper working temperature on the granule sheet.
      source: mueller-q51-fi
      where: Technical data table, Continuous working temperature row
uses:
  - application: electronics-and-chips
    device: Slot, phase and wedge insulation in electric motors (Teonex Q 51 and Q5100)
    example: Mueller-Ahlhorn says Teonex Q 51 was specially designed for slot and phase insulation and slot closure in electro motors with increased stress. SynFlex says Teonex Q5100 is for slot insulation, phase insulation and wedges in motors with increased load.
    source: mueller-q51-fi
    where: Applications section; SynFlex Application section for Q5100
  - application: electronics-and-chips
    device: Substrate for flexible integrated circuits
    example: Wikipedia says PEN is a substrate for flexible integrated circuits, positioned as a replacement for PET, and cites emerging use in modern electronic devices.
    source: wikipedia-pen
    where: Benefits section; Applications section
supply:
  - subject: Naphthalene-2,6-dicarboxylic acid (NDC or PNDA) and ethylene glycol, the monomers
    abundance: Indorama says PEN is made from ethylene glycol and either NDC or PNDA, and that its monomers are EU REACH registered. No abundance or feedstock figure was found in the sources checked.
    producers: []
    critical_lists: []
    recycling: No source found in the sources checked.
    substitutes: []
    source: indorama-pen-spec
    where: Introduction paragraph; regulatory note on REACH
documents:
  - title: Goodfellow technical data sheet, PEN Granules (SKU 1000082271, product ES36-GL-000100)
    type: datasheet
    url: https://www.goodfellow.com/global/technical_data/pdf/download?sku=1000082271
    year: 2024
  - title: Mueller-Ahlhorn data sheet, Teonex Q 51 FI 14090 (electrical insulating material)
    type: datasheet
    url: https://www.mueller-ahlhorn.com/wp-content/uploads/2024/02/Teonex-Q51-FI-14090-ENG.pdf
    year: 2024
  - title: SynFlex product datasheet, Teonex Q5100 (updated 06/24)
    type: datasheet
    url: https://www.synflex.com/fileadmin/user_upload/Teonex_R__Q5100.pdf
    year: 2024
  - title: Indorama Ventures sales specifications, Polyethylene Naphthalate (PEN), CAS 24968-11-4 / 25853-85-4
    type: datasheet
    url: https://www.indoramaventures.com/storage/downloads/product/intro-naphthalates/pen/en/PENINTRO.pdf
    year: 2021
  - title: Plabase property table, Teonex TN8050SC (Teijin Limited)
    type: database
    url: https://en.plabase.com/plastic/items/5bf4b186bfe33314ea415b5e
    year: 2026
  - title: Double glass transition in polyethylene naphthalate by MDSC, BDS, and TSDC (arXiv:2307.11537)
    type: paper
    url: https://arxiv.org/pdf/2307.11537
    year: 2023
  - title: Ageing of poly(ethylene terephthalate) and poly(ethylene naphthalate) under moderately accelerated conditions (Strathprints)
    type: paper
    url: https://strathprints.strath.ac.uk/42262/
    year: 2011
gaps:
  - No atomic-oxygen erosion yield or flight result for PEN was found. The MISSE PEACE report (NASA/TM-2001-211311) and the NASA/TM-2008-215490 table list PET and polyethylene but no PEN.
  - No PubChem record or GHS classification for PEN or for the monomers was read. PubChem returned a bot-check page and HTTP 400, so the monomer hazards (NDC, ethylene glycol) are not covered.
  - No supplier safety data sheet for a PEN grade was read. The Goodfellow SDS button is a placeholder link, and no Toyobo or Teijin SDS was found.
  - The NICNAS report on the dimethyl NDC monomer (NA/504, CAS 840-65-3) could not be downloaded in this pass, so its hazard classification is not covered.
  - The glass transition value differs by source and method. The 387 K value is a primary MDSC transition of a quenched sheet. A 121 °C value quoted in a national film archive glossary could not be opened (blocked), so it is not used.
  - Humidity and heat ageing have no numeric results. The Strath abstract gives only the temperatures and the qualitative result. Turnbull et al. (2012) full text was not accessible. Quantitative hydrolysis rate data were not found.
  - UV resistance has only the qualitative Goodfellow rating (Fair). No UV transmission or tensile-retention figure for PEN film was found.
  - Supply shares are missing. No USGS, EU or trade-association source covers PEN or naphthalene-2,6-dicarboxylic acid. Market-research pages name producers (DuPont Teijin Films, Toray, SKC, Sumitomo Chemical and others), but their shares conflict and were not used.
  - 'The grade named Teonex is printed under different owners: DuPont (Mueller-Ahlhorn), TOYOBO (SynFlex) and Teijin (plabase). Each property is tied to the grade and source on its own line.'
  - The NIST atomic-weight table gives C, H and O only as intervals (for example carbon 12.0096 to 12.0116), so the recipe gives atom counts in the role text and no atomic weights.
  - 'Media: no PEN image with a confirmed licence was read in this pass.'
  - Tekra product pages for Teonex Q 53 and Q 83 returned HTTP 403, so they are not used.
  - Volume and surface resistivity, intrinsic viscosity and dimensional shrinkage are printed in the sources but are not in property-canon.yaml, so they are left out.
sources:
  goodfellow-pen-tds:
    title: Goodfellow technical data sheet, PEN Granules (5mm, 10000 g), material properties for polymers
    id: SKU 1000082271; product code ES36-GL-000100; CAS 24968-11-4
    url: https://www.goodfellow.com/global/technical_data/pdf/download?sku=1000082271
    year: 2024
    kind: datasheet
    license: Supplier data sheet (cited, not reproduced)
  mueller-q51-fi:
    title: Dr. Dietrich Mueller GmbH, Teonex Q 51 FI 14090, electrical insulating material
    id: Teonex Q 51 FI 14090
    url: https://www.mueller-ahlhorn.com/wp-content/uploads/2024/02/Teonex-Q51-FI-14090-ENG.pdf
    year: 2024
    kind: datasheet
    license: Supplier data sheet (cited, not reproduced)
  synflex-q5100:
    title: SynFlex Elektro GmbH, product datasheet Teonex Q5100 (updated 06/24)
    id: Teonex Q5100
    url: https://www.synflex.com/fileadmin/user_upload/Teonex_R__Q5100.pdf
    year: 2024
    kind: datasheet
    license: Supplier data sheet (cited, not reproduced)
  indorama-pen-spec:
    title: Indorama Ventures, sales specifications of polyethylene naphthalate (PEN), June 2021
    id: CAS 24968-11-4 / 25853-85-4
    url: https://www.indoramaventures.com/storage/downloads/product/intro-naphthalates/pen/en/PENINTRO.pdf
    year: 2021
    kind: datasheet
    license: Supplier specification (cited, not reproduced)
  plabase-tn8050sc:
    title: Plabase property table, Teonex TN8050SC (Teijin Limited)
    id: plabase item 5bf4b186bfe33314ea415b5e
    url: https://en.plabase.com/plastic/items/5bf4b186bfe33314ea415b5e
    year: 2026
    kind: database
    license: Materials database (cited, not reproduced)
  arxiv-pen-mdsc:
    title: Double glass transition in polyethylene naphthalate by MDSC, BDS, and TSDC (Canadas et al.)
    id: arXiv:2307.11537
    url: https://arxiv.org/pdf/2307.11537
    year: 2023
    kind: paper
    license: arXiv preprint (cited)
  strath-ageing-2011:
    title: Ageing of poly(ethylene terephthalate) and poly(ethylene naphthalate) under moderately accelerated conditions, J. Appl. Polym. Sci.
    id: University of Strathclyde, Strathprints 42262
    url: https://strathprints.strath.ac.uk/42262/
    year: 2011
    kind: paper
    license: Open access repository record (cited)
  wikipedia-pen:
    title: Wikipedia, Polyethylene naphthalate
    id: CAS 24968-11-4 (Identifiers section)
    url: https://en.wikipedia.org/wiki/Polyethylene_naphthalate
    kind: web
    license: CC BY-SA 4.0 (cited, not reproduced)
license: CC-BY-4.0
updated: '2026-10-26'
review:
  status: draft
  method: assistant
  checked_values: 27
  unreachable: 6
  caveats: 6
  note: Read by an AI assistant on 2026-10-26 from fetched data sheets, a sales specification, an open preprint, an ageing paper and a materials database. PubChem, the Tekra pages and the NICNAS report could not be opened. No PEN flight erosion value was found.
story:
  recipe:
    line: PEN is a polyester made by joining naphthalene-2,6-dicarboxylic acid (or its dimethyl ester) with ethylene glycol through ester links. Each repeat unit (C14H10O4) has a naphthalene ring where PET has a benzene ring, and that larger aromatic ring stiffens the chain. Indorama describes PEN as analogous to PET but with improved thermal, barrier and UV properties.
    parts:
      - name: Carbon
        symbol: C
        role: Ten carbons in the naphthalene ring, two in the carboxyl groups and two in the ethylene linker.
      - name: Hydrogen
        symbol: H
        role: Six on the naphthalene ring and four on the ethylene linker.
      - name: Oxygen
        symbol: O
        role: Two ester groups, each with a carbonyl oxygen and an ether oxygen.
  risk_groups:
    - title: For people
      level: 0
      verdict: Not classified hazardous under OSHA criteria
      lead: The PEN sales specification says no hazard label is needed under OSHA criteria. No GHS record for PEN was found in the sources checked.
      points:
        - label: The resin
          line: Indorama's sales specification says no hazard warning is required on the label under OSHA criteria, and that the DOT shipping name is not regulated.
        - label: The film
          line: The Goodfellow data sheet rates the 0.075 mm film VTM-2 under UL 94, a thin-material vertical burn class.
        - label: Monomers
          line: The sales specification says the monomers are EU REACH registered. Their hazard data were not found in the sources checked.
    - title: If it overheats
      lead: The data sheets give the service limits. Above them the film is not rated.
      points:
        - label: Service limit
          line: The Mueller-Ahlhorn sheet gives a continuous working temperature of 160/180 °C (UL 746B) for Teonex Q 51. The Goodfellow sheet gives an upper working temperature of 155 °C.
        - label: Shrinkage
          line: The SynFlex sheet gives 0.4 % longitudinal shrinkage after 30 min at 150 °C, and 0.8 % at 200 °C, for 50 micron film.
    - title: Handling and storage
      points:
        - label: Moisture
          line: Water absorption is 0.3 % to 0.4 %. The ageing paper says PEN is thought to resist hydrolysis better than PET, but it gives no loss figures for hot, humid exposure.
        - label: Packing
          line: Pellets are sold in 1000 kg fabric bags or 100 kg fibre drums.
  why: Polyethylene naphthalate (PEN) is a polyester film and resin. It is the naphthalene analogue of PET, and the extra ring gives improved thermal properties, as Indorama says. The electrical grade Teonex Q 51 is rated for 160/180 °C in UL 746B service, and Mueller-Ahlhorn says Teonex has better properties than PET-polyester films, including temperature resistance. Its weakness is that its ageing behaviour is less studied than PET's, and no atomic-oxygen flight data were found.
  uses:
    - where: Electric motors
      line: Mueller-Ahlhorn says Teonex Q 51 was specially designed for slot and phase insulation and slot closure in electro motors with increased stress. SynFlex says Teonex Q5100 is for slot insulation, phase insulation and wedges.
    - where: Flexible electronics
      line: Wikipedia says PEN is a substrate for flexible integrated circuits and is positioned as a replacement for PET.
  can_do:
    - label: Heat
      benchmark: max_service_temp
      line: The electrical grade Teonex Q 51 is rated for a continuous working temperature of 160/180 °C under UL 746B. The granule sheet gives an upper working temperature of 155 °C.
    - label: Strength
      benchmark: ultimate_tensile_strength
      line: Biaxial PEN film has a tensile strength of 200 MPa. Teonex Q5100 at 50 micron has 290 MPa longitudinal and 300 MPa transversal.
    - label: Stiffness
      benchmark: elastic_modulus
      line: The TN8050SC resin grade has a tensile modulus of 2200 MPa (ISO 527). Biaxial film has 5 to 5.5 GPa.
    - label: Dielectric
      benchmark: dielectric_strength
      line: Teonex Q 51 lists a dielectric strength of 250 kV/mm (JIS C-2318), and the biaxial film lists 160 kV/mm at 0.075 mm.
  compare: Mueller-Ahlhorn says Teonex has better properties than PET-polyester films, including temperature resistance. The arXiv measurement gives a primary glass transition of 387 K (114 °C) for quenched PEN sheet, and the DSC melting point is 269 °C for the electrical grade. The continuous working temperature of 160/180 °C is the rating to compare with other electrical films. The compare table below sets PEN against the benchmarks it has values for.
  compare_rows:
    - label: Density
      benchmark: density
    - label: Melting point
      benchmark: melting_point
    - label: Glass transition temperature
      benchmark: glass_transition_temperature
  handling:
    - Obtain the current safety data sheet for the grade before use. Indorama says the customer should consult the SDS for any material.
    - Keep the film below its continuous working limit of 160/180 °C for electrical service.
    - Keep pellets in their supplied bags or drums until use, as the Indorama sheet describes the packing.
  good_for:
    - Motor slot and phase insulation, where the 160/180 °C rating and 250 kV/mm dielectric strength are used.
    - Flexible electronics substrates, where a higher glass transition than PET is wanted (Wikipedia).
  watch_out:
    - Ageing data are thin. No atomic-oxygen flight value, and no quantitative humidity or UV result, was found.
    - The shrinkage at 200 °C (0.8 % at 50 micron) means that hot processing needs control.
    - Trademark owners differ between the sources (DuPont, TOYOBO and Teijin), so check the grade and its data sheet.
  verdict: PEN is a heat-tolerant polyester film with a 160/180 °C electrical rating. It is a sound choice for motor insulation and flexible substrates, but its behaviour in vacuum, UV and humidity needs a grade-specific test before flight use.