What is PEEK (Polyetheretherketone)
Polyetheretherketone (PEEK) is a high-performance semi-crystalline thermoplastic known for its exceptional mechanical properties and chemical resistance. Since its introduction in the early 1980s, PEEK has been widely used in many demanding applications, particularly in aerospace, automotive, electronics, and medical devices.
Chemical and physical properties
Structure and Chemical Resistance
The molecular structure of Polyetheretherketone (PEEK) provides it with exceptional chemical resistance, enabling it to withstand corrosion from most acids, bases, and organic solvents. PEEK has a glass transition temperature of 143°C and a melting point of 343°C. At high temperatures, PEEK exhibits good resistance to halogens and strong acids, although it can dissolve in concentrated sulfuric acid at room temperature. These properties make PEEK highly suitable for applications in the chemical, pharmaceutical, and food processing industries.
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Mechanical Performance
Polyetheretherketone (PEEK) boasts impressive mechanical properties, with a Young's modulus of 3.6 GPa and a mechanical strength ranging from 90 to 100 MPa. The crystallinity of PEEK, which is influenced by processing conditions, plays a crucial role in determining its mechanical performance.
PEEK Melting Point and Thermal Expansion
Polyetheretherketone (PEEK) has a high melting point of 343°C, with certain grades allowing for continuous operation at temperatures up to 250°C. PEEK’s thermal conductivity increases linearly with temperature, showcasing its excellent thermal stability. Even in high-temperature or humid environments, PEEK maintains its superior electrical insulation properties, making it suitable for use in aircraft structural components and printed circuit boards (PCBs).
Medical Applications
PEEK is highly compatible with human tissues and fluids, making it widely used in medical devices and implants, such as orthopedic implants. Its biocompatibility and corrosion resistance make PEEK an essential material for manufacturing various medical equipment.
Electrical Insulation Properties
PEEK offers excellent electrical insulation properties, maintaining stability even in high-temperature or humid environments. This makes PEEK an ideal choice for insulating materials in aircraft structural components and printed circuit boards (PCBs).
Chemical resistance chart
» Meaning of symbol:
OK: Recommended. △: Must confirm if usable by testing in advanced. X: Not recommended.
» This chart only provides the result of a single chemical to material, if a client uses more than one kind of chemical at the same time, please choose material by experience.
» This chart is for reference only which is not applicable to all working environments. Please refer to design equipment according to practical experience.
| Category |
Name |
PEEK |
Organic acids
|
Acetic acid |
OK (10% @ 23˚C, 100˚C)
OK (Conc. @ 23˚C, 100˚C) |
| Acetic acid, glacial |
OK (23˚C, 100˚C) |
| Acetic anhydride |
N/A |
| Citric acid |
OK (23˚C, 100˚C) |
Organic compound
|
Acetaldehyde |
OK (23˚C, 100˚C) |
| Acetone |
OK (23˚C, 100˚C) |
| Methyl alcohol |
N/A |
| Aniline |
OK (23˚C)
△ (100˚C) |
| Benzaldehyde |
OK (23˚C) |
| Benzene |
OK (23˚C, 100˚C) |
| Benzyl alcohol |
OK (23˚C) |
| Benzyl chloride |
N/A |
| Corn oil |
N/A |
| Ethanol |
OK (23˚C, 100˚C) |
| Ethylene glycol |
OK (23˚C, 100˚C) |
| Fatty acid |
OK (23˚C, 100˚C) |
| Formaldehyde |
OK (23˚C, 100˚C) |
| Formic acid |
△ (23˚C, 100˚C) |
| Hexane |
OK (23˚C) |
| Lactic acid |
OK (23˚C, 100˚C) |
| Methanol |
OK (23˚C, 100˚C) |
| Paraffin oil |
N/A |
| Petroleum |
N/A |
| Phenol |
X (Conc.) |
| Propane, liq |
OK (23˚C) |
| Propanol |
OK (23˚C) |
| Stearic acid |
N/A |
| Tannic acid |
X (10% Conc. @ 23˚C, 100˚C) |
| Tartaric acid |
X (23˚C, 100˚C) |
| Toluene |
OK (23˚C) |
| Urea |
OK (23˚C, 100˚C) |
Inorganic compound
|
Ammonia |
OK (23˚C) |
| Ammonium chloride |
N/A |
| Ammonium hydroxide |
OK (10% Conc. @ 23˚C)
OK (Conc. @ 23˚C) |
| Ammonium nitrate |
N/A |
| Ammonium sulfate |
N/A |
| Aqua regia |
X (23˚C, 100˚C, 200˚C) |
| Barium chloride |
OK (23˚C) |
| Barium hydroxide |
N/A |
| Brine |
OK (23˚C, 100˚C) |
| Calcium Chloride |
OK (23˚C, 100˚C) |
| Calcium hydroxide |
N/A |
| Carbonic acid |
OK (23˚C, 100˚C) |
| Chloric acid |
N/A |
| Chlorine |
X (23˚C, 100˚C, 200˚C) |
| Detergent |
OK (non-phenolic @ 23˚C, 100˚C) |
| Hydrobromic acid |
OK (20%)
X (100% @ 23˚C, 100˚C, 200˚C) |
| Hydrochloric acid |
OK (10% Conc. @ 23˚C, 100˚C)
OK (Conc. @ 23˚C)
△ (Conc. @ 100˚C) |
| Hydrofluoric acid |
X (40%, Conc. @ 23˚C, 100˚C, 200˚C) |
| Hydrogen peroxide |
OK (23˚C, 100˚C) |
| Nitric acid |
OK (10% Conc. @ 23°C,100°C)
△(30% Conc. @ 23°C)
X (50% Conc. @ 23°C,100°C, 200°C)
X (Conc. @ 23°C,100°C, 200°C) |
| Phosphoric acid |
OK (10% Conc. @ 23°C,100°C, 200°C)
OK (50% Conc. @ 23°C,100°C, 200°C)
OK (80% Conc. @ 23°C,100°C) |
| Potassium hydroxide |
OK (10% Conc. @ 23°C)
OK (70% Conc. @ 23°C) |
| Potassium nitrate |
OK (23°C,100°C) |
| Potassium sulfate |
OK (23°C,100°C) |
| Sodium carbonate |
OK (23°C,100°C) |
| Sodium hydroxide |
OK (10% Conc. @ 23°C,100°C, 200°C)
OK (50% Conc. @ 23°C,100°C, 200°C)
OK (Conc. @ 23°C) |
| Sodium nitrate |
OK (23°C,100°C) |
| Sulfuric acid |
△ (<40% Conc. @ 23°C,100°C, 200°C)
X (>40% Conc. @ 23°C,100°C, 200°C) |
| Sulfur dioxide |
OK (23°C, 100°C, 200°C) |