Polyethersulfone PES

Poly(oxy-1,4-phenylenesulfonyl-1,4-phenylene), repeat unit C12H8O3S, made from a diphenol and 4,4'-dichlorodiphenyl sulfone · CAS 25608-63-3

Also known as E2010

Polyethersulfone (PES) is an amorphous, high-temperature thermoplastic made from a diphenol and 4,4'-dichlorodiphenyl sulfone.

9 sources · Updated 2026-10-26 · CC BY 4.0

Evidence level

2 of 5

Lab-measured

Heat

205 degC

Glass transition

225 degC

Stiffness

2640 MPa

Long-term heat

180 degC

Recipe, share of the weight

  • C 62.1%Carbon
  • H 3.5%Hydrogen
  • O 20.7%Oxygen
  • S 13.8%Sulfur

Best for

Electrical and structural parts that must keep their shape at about 205 degC (heat deflection at 1.8 MPa) and need a UL V-0 flame class at 1.5 mm

Weakest at

Ultraviolet light and oxygen: UV breaks the polymer chain and forms sulfonic acid groups when oxygen is present, and no PES flight or radiation result was found

Risk at a glance

  • People None found. Not classified hazardous
  • If it fails Moderate. UV-driven chain scission at exposed surfaces
  • Corrosion Moderate. Under UV at 365 nm, PES microplastics released more bisphenol S the hotter the water was.

Quick facts: PES

Key properties of PES
PropertyValueBasis
Density1.37 g/cm³1 sourced value
Yield strength86 MPa1 sourced value
Young's modulus2.64 GPa1 sourced value
Thermal expansion (CTE)52 to 59 ppm/K2 sourced values across conditions
Maximum service temperature220 °C1 sourced value

What is the density of Polyethersulfone (PES)?

Polyethersulfone (PES) has a density of 1.37 g/cm³. The source and test conditions are listed in the properties table on this page.

What is the coefficient of thermal expansion of Polyethersulfone (PES)?

Polyethersulfone (PES) has a coefficient of thermal expansion of 52 to 59 ppm/K. 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 the yield strength of Polyethersulfone (PES)?

Polyethersulfone (PES) has a yield strength of 86 MPa. The source and test conditions are listed in the properties table on this page.

What is the Young's modulus of Polyethersulfone (PES)?

Polyethersulfone (PES) has a Young's modulus of 2.64 GPa. The source and test conditions are listed in the properties table on this page.

What is the maximum service temperature of Polyethersulfone (PES)?

Polyethersulfone (PES) has a maximum service temperature of 220 °C. The source and test conditions are listed in the properties table on this page.

What is Polyethersulfone (PES) used for?

Uses recorded in the sources include Electrical components; Headlight bezel (automotive).

Why it exists

Polyethersulfone (PES) is an amorphous thermoplastic whose backbone is phenylene, ether and sulfone links, with no isopropylidene group. That makes it a sulfone-only polymer, which is why it sits alongside PSU in the polysulfone family but differs from it in its repeat unit and in its heat limit. BASF's unreinforced E 2010 grade gives a glass transition of 225 degC, a deflection temperature of 205 degC at 1.8 MPa and a tensile modulus of 2640 MPa. It was chosen for this profile because it is a heat-resistant sulfone polymer whose flame and electrical data are well documented in a manufacturer datasheet.

Where it's used

Electrical components

Plabase lists the main application of Sumikaexcel PES 4101GL30 as electrical components. That is a grade with a glass-fibre suffix, not the unfilled natural grade profiled here.

Vehicle parts

BASF's range chart shows a headlight bezel among its application pictures for the Ultrason E, S and P family. The picture does not name a grade.

Recipe

Poly(oxy-1,4-phenylenesulfonyl-1,4-phenylene), repeat unit C12H8O3S, made from a diphenol and 4,4'-dichlorodiphenyl sulfone

PES is made by polycondensation of a diphenol with 4,4'-dichlorodiphenyl sulfone. Wikipedia names the diphenol as bisphenol A or 1,4-dihydroxybenzene; the PES systematic name has no isopropylidene group, so the diphenol here is the hydroquinone type. The repeat unit is C12H8O3S.

What PES is made of
IngredientAtoms per unitShare of the weightWhat it does
Carbon C 12 62.1% Forms the two phenylene rings of each repeat unit.
Hydrogen H 8 3.5% Four hydrogens on each phenylene ring.
Oxygen O 3 20.7% One ether oxygen and the two oxygens of the sulfone group.
Sulfur S 1 13.8% Sulfone group, which gives the polymer its rigidity and heat resistance.

Weight shares are calculated from standard atomic weights.

What it can do

Heat

205 degC

measured

BASF's unreinforced E 2010 NAT datasheet gives a deflection temperature of 205 degC at 1.8 MPa (ISO 75 HDT/A).

Glass transition

225 degC

measured

BASF's DSC value is 225 degC, and the Röchling sheet prints the same 225 for the glass transition.

Stiffness

2640 MPa

measured

The tensile modulus is 2640 MPa at 23 degC by ISO 527-1/-2.

Long-term heat

180 degC

measured

BASF gives an IEC 60216 index of 180 degC, meaning a 50 percent fall in tensile strength after 20000 h.

How it compares

Compared with PSU, PES has no bisphenol-A unit, so its repeat unit is smaller and more rigid in the sulfone-ether backbone. In the datasheets in this run, PES gives a deflection temperature of 205 degC at 1.8 MPa and a glass transition of 225 degC. The PSU profile has a lower deflection temperature and a different moisture figure, measured on another basis, so the two should be compared with care. Neither profile has a flight atomic oxygen value that applies to the other: PES has none in this run.

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.

Benchmarks
MeasurementPESPAIPBIPBO (Zylon)PEEKPEIPEKPEKKPPSPPSUPSU
Thermal behavior and safety
Deflection temperature under load, 1.8 MPa205 °C2278 °C435 °Cno datano data173 °C163 °C164 °C400 °F207 °C174 °C
Relative thermal index, 50 percent loss of tensile strength after 20000 h180 °C4no datano datano datano datano datano datano datano data105 °Cno data
Thermal decomposition temperature, lower bound> 400 °C21no datano datano datano datano datano datano datano datano datano data
Lifetime and stability
Melt volume-flow rate, 360 degC and 10 kg70 cm³/10min20no datano datano datano datano datano datano datano datano datano data
Physical and electrical
Density, unreinforced natural grade1370 kg/m351.41 g/cc1.276 g/cm³1.398 g/cm³1.3 g/cm³1.34 g/cm³1.3 g/cm³1.29 g/cm³1.36 g/cm³1.29 g/cm³1.22 g/cm³
Temperature behavior
Glass transition temperature, unreinforced natural grade225 °C1275 °C425 °Cno datano data186 °C160 °C165 °C90 °C220 °C190 °C
Ignition temperature, lower bound> 510 °C22no datano datano datano datano datano datano datano datano data549 °C
Other measurements
Maximum service temperature for a few hours220 °C3260 °C260 °Cno datano datano datano datano data338 °Fno datano data
Water absorption at saturation in water, 23 degC2.2 %60.4 %0.4 %no datano data0.25 %0.6 %0.4 %0.01 %1.1 %0.3 %
Moisture absorption at equilibrium, standard atmosphere0.8 %70.4 %0.4 %no datano data0.25 %0.6 %0.4 %0.01 %1.1 %0.3 %
Tensile modulus, unreinforced natural grade2640 MPa84136 MPa5.9 GPa147.1 GPano data3200 MPa4300 MPa4000 MPa8.37×10^5 psi2340 MPa2480 MPa
Yield stress, tensile, 50 mm per min86 MPa9no datano datano datano data110 MPa115 MPa110 to 120 MPa13700 psi74 MPano data
Notched Izod impact strength, 23 degC7.5 kJ/m210105 J/mno datano datano data88 J/mno datano datano data690 J/m69 J/m
Notched Izod impact strength, -30 degC8 kJ/m211105 J/mno datano datano data88 J/mno datano datano data690 J/m69 J/m
Linear thermal expansion coefficient, longitudinal, 23 to 80 degC52 E-6/K123.1×10^-5 1/°C23 10-6 K-1no datano data5.2×10^-5 1/°C55 ppm/K23 µm/m/K2.6×10^-5 cm/cm/°C55 E-6/K5.6×10^-5 1/°C
Linear thermal expansion coefficient, longitudinal, 180 degC59 E-6/K133.1×10^-5 1/°C23 10-6 K-1no datano data5.2×10^-5 1/°C55 ppm/K23 µm/m/K2.6×10^-5 cm/cm/°C55 E-6/K5.6×10^-5 1/°C
Relative permittivity at 100 Hz3.9 -144.2 -3.2 -no datano datano datano data3 -3 -3.44 -3.03 -
Relative permittivity at 1 MHz3.8 -154.2 -3.2 -no datano datano datano data3 -3 -3.44 -3.03 -
Dielectric loss factor at 100 Hz17 E-416no datano datano datano datano datano data0.002 -0.001 -no datano data
Dielectric loss factor at 1 MHz140 E-417no datano datano datano datano datano data0.002 -0.001 -no datano data
Dielectric strength, K20/K2037 kV/mm18580 V/mil21 kV/mmno datano datano data23 kV/mm84 kV/mm450 V/mil15 kV/mm17 kV/mm
Refractive index, 1 mm specimen1.63 -19no datano datano datano datano datano datano datano data1.672 -no data

Why choose it, and why not

Good for

  • Parts that must hold their shape at 205 degC or more under a 1.8 MPa load, such as the electrical components and headlight bezels named in the uses section.
  • Flame-rated parts: BASF's UL yellow card gives V-0 at 1.5 mm.
  • Long-term use near 180 degC, according to BASF's IEC 60216 index.

Watch out for

  • UV in air breaks the chains and forms sulfonic acid groups, so exposed surfaces need protection. No PES flight result was found.
  • Water uptake of 2.2 percent at saturation changes dimensions and must be allowed for in close-tolerance parts.
  • PES is not a space-qualified material on the evidence in this profile: no atomic oxygen or radiation result was found.

PES is a stiff, heat-tolerant, flame-rated sulfone thermoplastic with well-documented datasheet values. For space use it still needs UV and atomic oxygen protection, and no flight evidence was found.

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.

Other names and standards
SystemCodes
Trade nameE2010

Notes

The method, full conditions and any caveat for the numbered rows above.

Notes for the numbered rows
#MeasurementMethodConditionsCaveat
1Glass transition temperature, unreinforced natural gradeGuideline value as printed in the BASF product information (German text), row 'Glasubergangstemperatur, DSC (10 degC/min)'. The Röchling handling sheet also prints 225 for the glass transition temperature, with no unit.grade Ultrason E 2010 NAT (unreinforced, natural colour)method standard ISO 11357-1/-2, DSC at 10 °C per minbasis guideline value printed in a table headed 'at 23 °C' for the uncoloured productThe Röchling Sustason PES natural handling sheet prints the same figure, 225, in its Product characteristics section. Its unit is not printed.
2Deflection temperature under load, 1.8 MPaValue as printed in the BASF product information, thermal properties table, ISO 75-1/-2 HDT/Agrade Ultrason E 2010 NAT (unreinforced)load 1.8 MPamethod standard ISO 75-1/-2, method A (HDT/A)—
3Maximum service temperature for a few hoursExperience value as printed in the BASF thermal properties table (footnote 3); not a test resultduration up to a few hoursbasis BASF experience value for parts that must hold up to this temperature for a few hours, repeated over years, with material-appropriate design and processing—
4Relative thermal index, 50 percent loss of tensile strength after 20000 hTemperature index as printed in the BASF thermal properties table; the UL yellow card for the same grade prints relative thermal indices of 180 degC (electrical and impact) and 190 degC (strength) for 1.5 mmbasis IEC 60216 temperature index for 50 percent decrease of tensile strength after 20000 h; the footnote says some values are expected rather than measuredflame class V-0 at 1.5 mm (UL yellow card E41871, ALL colours)Snake-case name used because no canonical name fits the IEC 60216 index. The UL yellow card also prints a strength index of 190 degC (see gaps).
5Density, unreinforced natural gradeDensity as printed in the BASF product information, row Dichte (ISO 1183)grade Ultrason E 2010 NAT (unreinforced)method standard ISO 1183—
6Water absorption at saturation in water, 23 degCValue as printed in the BASF product information, row Wasseraufnahme, Sattigung in Wasser bei 23 degCtemperature 23 °Cmedium waterendpoint saturationmethod standard similar to ISO 62—
7Moisture absorption at equilibrium, standard atmosphereValue as printed in the BASF product information, row Feuchtigkeitsaufnahme, Sättigung bei Normalklima 23 degC / 50 % r.F.temperature 23 °Crelative humidity 50 percentendpoint equilibriummethod standard similar to ISO 62—
8Tensile modulus, unreinforced natural gradeValue as printed in the BASF product information, mechanical properties table, row Zug-E-Modul (ISO 527-1/-2)grade Ultrason E 2010 NAT (unreinforced)method standard ISO 527-1/-2temperature 23 °C—
9Yield stress, tensile, 50 mm per minValue as printed in the BASF product information, row Streckspannung, 50 mm/min (ISO 527-1/-2). The datasheet gives no tensile strength at break.grade Ultrason E 2010 NAT (unreinforced)method standard ISO 527-1/-2test speed 50 mm/mintemperature 23 °C—
10Notched Izod impact strength, 23 degCValue as printed in the BASF product information, row Izod-Kerbschlagzähigkeit (23 degC), ISO 180/Agrade Ultrason E 2010 NAT (unreinforced)method standard ISO 180/Atemperature 23 °C—
11Notched Izod impact strength, -30 degCValue as printed in the BASF product information, row Izod-Kerbschlagzähigkeit (-30 degC), ISO 180/Agrade Ultrason E 2010 NAT (unreinforced)method standard ISO 180/Atemperature -30 °C—
12Linear thermal expansion coefficient, longitudinal, 23 to 80 degCValue as printed in the BASF product information (52 E-6/K, the unit the source prints; the registry reads E-6/K as ppm/K)temperature range 23 to 80 °Cdirection longitudinalmethod standard ISO 11359-1/-2—
13Linear thermal expansion coefficient, longitudinal, 180 degCValue as printed in the BASF product information (59 E-6/K, the unit the source prints; the registry reads E-6/K as ppm/K)temperature 180 °Cdirection longitudinalmethod standard DIN 53752—
14Relative permittivity at 100 HzValue as printed in the BASF product information, electrical properties tablefrequency 100 Hzmethod standard IEC 62631-2-1—
15Relative permittivity at 1 MHzValue as printed in the BASF product information, electrical properties tablefrequency 1 MHzmethod standard IEC 62631-2-1—
16Dielectric loss factor at 100 HzValue as printed in the BASF product information, row Dielektr. Verlustfaktor (100 Hz); the source uses a power-of-ten unit, kept as printedfrequency 100 Hzmethod standard IEC 62631-2-1unit in source E-4 (printed as 17)—
17Dielectric loss factor at 1 MHzValue as printed in the BASF product information, row Dielektr. Verlustfaktor (1 MHz); kept as printedfrequency 1 MHzmethod standard IEC 62631-2-1unit in source E-4 (printed as 140)—
18Dielectric strength, K20/K20Value as printed in the BASF product information, row Durchschlagfestigkeit K20/K20, IEC 60243-1method standard IEC 60243-1specimen treatment K20/K20 as printed in the datasheet—
19Refractive index, 1 mm specimenValue as printed in the BASF product information, optical properties tablespecimen thickness 1 mmmethod standard ISO 489—
20Melt volume-flow rate, 360 degC and 10 kgValue as printed in the BASF product information, row Schmelzevolumenrate MVR 360 degC/10 kg (ISO 1133). This is a volume rate, not the g/10 min melt flow rate used for PSU.temperature 360 °Cload 10 kgmethod standard ISO 1133Snake-case name used because no canonical name fits a volume-flow rate (see gaps).
21Thermal decomposition temperature, lower boundPrinted value in the Product characteristics section of the Röchling handling sheetbasis printed as greater than 400 °C in the supplier's handling sheet; test method and heating rate not stated—
22Ignition temperature, lower boundPrinted value in the Product characteristics section of the Röchling handling sheet; the sheet labels it ignition temperaturebasis printed as greater than 510 °C in the supplier's handling sheet; test method not stated—

Corrosion and compatibility

What happens when it meets other materials and environments.

Corrosion and compatibility
EnvironmentConcernWhat happens
Ultraviolet light in air (laboratory photolysis of PES films and membranes, UV at 199, 260 and 315 nm) not rated UV attacks PES: chain scission dominates, and sulfonic acid groups form only where oxygen is present.1
UV-A and UV-B photoaging of PES microplastics in water moderate Under UV at 365 nm, PES microplastics released more bisphenol S the hotter the water was.2
Humid air and immersion in water (23 degC) low PES takes up little water: 0.8 percent at 50 percent relative humidity and 2.2 percent at saturation.3
Long-term heat in air (thermal ageing) low The IEC thermal index is 180 degC, with 50 percent strength loss after 20000 h.4
Chemical exposure (acids, alkalis, solvents, oxidants) not rated Resistant to dilute acids and alkalis across pH 2 to 13, but not to aromatic hydrocarbons or low-polarity solvents.5
Corrosion details
#EnvironmentDetailsTest conditions
1 Ultraviolet light in air (laboratory photolysis of PES films and membranes, UV at 199, 260 and 315 nm) Norrman and Krebs irradiated PES at 199, 260 and 315 nm. Sulfonic acid groups (-SO3H) formed only in an oxygen-containing atmosphere, hydroxyl groups formed at all wavelengths and in all atmospheres, and chain scission was the dominant process. In vacuum, cross-linking was important instead. The abstract gives no dose or time, so no lifetime can be derived from it. wavelengths 199, 260 and 315 nmatmosphere oxygen-containing air, and vacuum for comparisondose or time not given in the abstract
2 UV-A and UV-B photoaging of PES microplastics in water Li and co-workers aged PES and polyphenylsulfone microplastics from baby bottles under UV. Hydroxyl radicals broke the ether bonds, which released bisphenol S (BPS). At 365 nm, the highest release at 50 degC was 3.2 times that at 25 degC and 1.7 times that at 35 degC. Humic acid at 10 mg/L or less increased release, and at 10 to 50 mg/L it reduced it. Absolute release concentrations are not in the abstract. wavelength UV365 and UV254 in the studytemperatures 25, 35 and 50 °Chumic acid 10 mg/L and 10 to 50 mg/L rangesmaterial baby-bottle-derived PES microplastic
3 Humid air and immersion in water (23 degC) BASF's guideline values show 0.8 percent moisture uptake at standard atmosphere (23 degC, 50 percent relative humidity) and 2.2 percent at saturation in water at 23 degC. The Ultrason range chart lists superior hydrolysis resistance among the main features. Wikipedia says polysulfones resist hydrolysis, aqueous and alkaline media, and autoclave and steam sterilisation. humidity 50 percent relative humidity (standard atmosphere, 23 °C)immersion saturation in water at 23 °Cmethod standard similar to ISO 62
4 Long-term heat in air (thermal ageing) BASF gives a relative temperature index of 180 degC for a 50 percent decrease in tensile strength after 20000 h (IEC 60216), and 220 degC as the maximum for a few hours. The Röchling sheet gives a thermal decomposition above 400 degC. Oxidation and chain effects at heat are not quantified beyond these figures. basis IEC 60216 temperature index, 20000 h, 50 percent tensile strength decreaseshort term a few hours at 220 °C maximum (experience value)
5 Chemical exposure (acids, alkalis, solvents, oxidants) Wikipedia gives PES, as a polyarylethersulfone, as highly resistant to mineral acids, alkali and electrolytes at pH 2 to 13, and resistant to oxidising agents although it degrades over time. It is not resistant to low-polarity organic solvents or aromatic hydrocarbons, and it dissolves in dichloromethane and N-methylpyrrolidone. The article gives no concentrations or times. basis qualitative statements in the Wikipedia article; no concentration, temperature or time given

Risks and side effects

Hazards to people, what happens when a cell overheats, and how the material is handled and stored.

For people

The handling sheet from Röchling and BASF's safety statement do not classify PES as hazardous. Dust and hot melt still need care.

The pellets
The Röchling sheet lists no labelled components, no special risks and no transport hazard. BASF says there are no harmful health effects when the product is handled as intended.
Dust
BASF applies the German MAK dust limit and asks for extraction over the barrel unit.
Hot melt
Processing at or below 390 degC gives no harmful vapours, according to BASF. Overheating breaks the polymer down.

If the polymer overheats or burns

Decomposition is slow to begin: the sheet gives a thermal decomposition above 400 degC and an ignition temperature above 510 degC.

Gases
A fire gives off carbon monoxide, sulfur dioxide and sulfur trioxide. Firefighters need self-contained breathing apparatus.
Water
Molten product should be cooled with water spray.

Handling and storage

Drying
Dry the pellets for at least 4 h at 130 to 150 degC before processing.
Storage
Store horizontally, dry and protected from climatic conditions.

Test details
The original wording and numbers from the sources, for readers who want them.

Failure risks

Failure risks
FailureTrigger and consequence
UV-driven chain scission at exposed surfacesmoderate severityUV exposure in an oxygen-containing atmosphereChain scission dominates and sulfonic acid groups form, which changes the surface. The abstract gives no dose or time, so no lifetime for exposed parts can be stated.
Loss of strength during long heat exposurelow severityContinuous heat near 180 degCBASF's relative thermal index is 180 degC for a 50 percent fall in tensile strength after 20000 h. Parts run near that temperature for years need design margin.
Dimensional change from water uptakelow severityImmersion or long exposure to humid airWater uptake is 0.8 percent at 50 percent relative humidity and 2.2 percent at saturation, so parts that swell or shift dimensions need allowance for it.

Side effects on surrounding parts

Side effects on surrounding parts
AffectsEffect
Operators and the processing areaOverheating or long melt residence releases decomposition gases. BASF advises purging decomposed melt into the open air, cooling it quickly in water, and not dismantling a hot barrel.
Responders and the local airIn a fire the product gives off carbon monoxide, sulfur dioxide and sulfur trioxide. Firefighters need full protective clothing and self-contained breathing apparatus.

Handling and storage

  • Dry the pellets for at least 4 h at 130 to 150 degC (vacuum or dry-air dryer) before processing, because they take up moisture.
  • Store horizontally, dry and protected from climatic influences. Let machined parts reach room temperature, or stand them for at least 24 h under normal conditions, before machining.
  • Apply the general dust limit under the German MAK value guidelines, and provide extraction over the barrel unit.

Mitigations

  • Fire: cool molten product with water spray. Suitable extinguishing media are water, foam, dry powder and CO2.

Supply and geography

How common the raw materials are and where they come from.

Sulfur (sulfone-group feedstock for 4,4'-dichlorodiphenyl sulfone)

Top producers (2025)
China 22.6%, United States 9.6%, Russia 8.9%, Canada 6%
Critical mineral lists
US: not listed
Recycling
The USGS sulfur chapter says 2.5 to 5 million tons of spent sulfuric acid is reclaimed a year from petroleum refining. That is sulfuric acid, not elemental sulfur from polymers.
Substitutes
USGS: substitutes for sulfur at present or anticipated prices are not satisfactory; some acids may replace sulfuric acid at higher cost.