Polymer Data File:
Polyether sulphone
- PES
Polymer Data File:Polyether sulphone
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Introduction
PES is a high temperature amorphous engineering thermoplastic with excellent thermal stability, an ability to withstand loads at temperatures of up to 180oC for long periods and an ability to retain many mechanical and electrical properties at temperatures up to 210oC. The material is tough and rigid at all temperatures to 210oC. Creep performance is good especially when glass reinforced.
Products are dimensionally stable at temperatures up to 210oC.
Typical
Applications
Automotive: Cooling system fans and other high temperature applications.
Electrical engineering: Relay and switch bodies, injection moulded printed circuit boards, lamp reflectors.
Domestic: Hot water meters and valves, electrically heated styling brushes.
Medicine: Laboratory centrifuges, lamps and reflectors, dental equipment.
Others: Aviation electrical components, weapons systems components, plastic bearing cages, radomes, oven components.
Physical
and Mechanical Properties
General physical properties
PES is a high temperature engineering thermoplastic that retains many properties up to high temperatures (in the region of 210oC) but also retains many properties down to -70oC.
Mechanical properties
Creep performance is good to high temperatures (especially when glass reinforced).
Property
Approximate Value
PES
PES (30% GF)
Tensile strength
80 - 105 MN/m2
>105 MN/m2
Tensile Modulus
2-3 GN/m2
>4 GN/m2
Elongation at Break
50 - 100 %
<10 %
Flexural Strength
100 - 150 MN/m2
150 - 200 MN/m2
Notched Impact Strength
3 - 10 kJ/m2
3 - 10 kJ/m2
Specific Heat
N/A
N/A
Glass Transition Temperature
230 oC
230 oC
Heat Deflection Temperature
200 - 250 oC
200 - 250 oC
Coefficient of Thermal Expansion
5 - 10 x 10-5 / oC
<5 x 10-5 / oC
Long Term Service Temperature
150 - 200 oC
150 - 200 oC
Specific Gravity
1.2 to 1.4
1.4 to 1.6
Mould Shrinkage
0.01 - 0.025 m/m
0.005 - 0.01 m/m
Water Absorption
0.1 - 0.5 % (50% rh)
0.1 - 0.5 % (50% rh)
Transparency
Transparent
Opaque
Thermal,
Electrical and Optical Properties
Thermal properties
PES has a UL temperature index of 180oC and retains dimensional stability to high temperatures.
Fire behaviour
PES has low flammability and has a UL 94 V-0 rating down to thicknesses of 0.43mm. Smoke and toxic gas emissions are low during burning.
Electrical properties
PES has excellent electrical insulation properties but tracking resistance is not good
PES is radar transparent.
Optical properties
N/A
Natural colour
Natural colour is translucent amber/brown. Can be dyed for transparent colours or pigmented for opaque colours.
Chemical
Resistance Properties
General
PES is resistant to oils and petrol at high temperatures and is resistant to a wide pH range of acids and alkalis. It is also resistant to aliphatic hydrocarbons, alcohols, benzene, fats and cleaning and degreasing agents.
PES is not resistant to concentrated mineral acids, ketones, chlorinated and aromatic hydrocarbons and many organic materials (chloroform, acetone, cyclohexanone, ethyl acetate etc.).
PES has excellent hydrolysis resistance and can withstand long term loads in contact with pressurised water at 150oC. Glass reinforced grades are particularly good in this type of application.
PES can be sterilised using most common hospital sterilisation methods.
Weathering and resistance to stress cracking
PES can be used for long term outdoor exposure only when protected by carbon black pigments or UV stabilisers.
Advantages and
Limitations
Advantages
Limitations
1. Excellent high temperature properties.
1. High cost
2. Excellent creep resistance.
2. Narrow processing window and high temperatures needed.
3. Good chemical resistance to common chemicals at elevated temperatures.
3. High levels of moulded in stress possible.
Processing
PES can be processed using conventional injection moulding and extrusion equipment and close tolerances can be achieved. Processing temperatures should not be increased too much otherwise overheating and darkening can occur.
PES should be dried at 150oC for 3 hours before processing to give less than 0.04% water content.
Injection moulding
PES has a high melt viscosity and suffers from burning if the temperature or shear rate is too high. This gives a narrow processing window and care needs to be taken in processing to avoid overshearing the material.
Melt temperature of 360oC using a screw with an L/D of 20:1. Use a high injection speed with a low screw speed (to minimise shear rate and shear degradation) and an injection pressure of 2000 bar /1200 bar. Mould temperature should be around 150oC
Sprue removal is by cropping while the material is still hot.
The high processing temperatures can give rise to concerns with moulded-in stress and it is recommended that mouldings are annealed after moulding at 160 - 200oC
Extrusion
Melt temperatures should be in the region of 300 - 360oC.
Up to 30% PES can be reground and recycled after drying.
Processing Method
Applicable
Injection Moulding
Yes.
Extrusion
Yes
Extrusion Blow Moulding
Yes
Rotational Moulding
No
Thermoforming
No
Casting
Yes
Bending and joining
Yes
Finishing
Machining
PES can be machined or cropped.
Surface treatment
PES can be vacuum metallised, electroplated, painted or etched
Welding
PES can be welded by friction, heat and ultrasound welding.
Bonding
Solvent weld with methylene chloride.
Health
and Safety
Health and Safety
PES has no significant Health and Safety implications and has been approved for use in contact with potable water and for food contact.
Other
Information
Identification
- Sinks in water.
- Does not burn easily but gives off white flame and odour of sulphur with little smoke emission.
- Tapping gives metallic ring.
Last edited: 14/11/2005
© Tangram Technology Ltd. 2001
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