Comprehensive Analysis of Polyetheretherketone (PEEK)

I. Physical and Chemical Properties

Polyetheretherketone (PEEK, CAS No.: 29658-26-2) is a semi-crystalline thermoplastic special engineering plastic. Its molecular chain is alternately connected by ether bonds (-O-), ketone bonds (-CO-), and benzene rings, endowing it with excellent comprehensive properties. The core characteristics are as follows:

1. Physical Properties

• Density: 1.3 g/cm³. The density of modified materials is much lower than that of metals (e.g., the density of aluminum alloy is 2.7 g/cm³), enabling lightweight advantages.
• Thermal Stability:
  • Melting point is 334°C, and the continuous service temperature reaches 260°C. The heat distortion temperature (HDT) of glass fiber-reinforced type is 310°C, and that of carbon fiber-reinforced type is 320°C.
  • Thermal decomposition temperature is 550°C. It can be processed by injection molding and extrusion within a wide temperature range of 340~420°C.
• Mechanical Strength:
  • Tensile strength is 92 MPa, and elastic modulus is 3.8 GPa. After carbon fiber reinforcement, the tensile strength increases to 210 MPa, and its specific strength exceeds that of steel.
  • It has excellent fatigue resistance. Under alternating stress, it can replace metal gears, with a service life increased by more than 3 times.
• Electrical Properties:
  • Dielectric loss is as low as 0.002 (at 1 MHz), and dielectric strength is >20 kV/mm. It still maintains stable insulation performance in high-temperature and high-humidity environments.
  • Surface resistivity is controllable (10⁵~10⁸ Ω/m²), meeting the anti-static requirements of electronic components.

2. Chemical Stability

• It has extremely strong corrosion resistance. Except for concentrated sulfuric acid, it is insoluble in any organic solvents, strong acids, and strong alkalis. Its performance does not decrease significantly after being soaked in boiling water for 800 hours.
• It has excellent hydrolysis resistance and can be used for high-pressure steam sterilization (134°C, 2 hours), meeting the requirements of medical-grade sterilization.

3. Other Characteristics

• Flame Retardancy: It can reach UL 94 V-0 grade without adding flame retardants, and produces extremely low smoke during combustion.
• Biocompatibility: It complies with the ISO 10993 standard, has no cytotoxicity, and can be implanted into the human body.
• Wear Resistance: The friction coefficient is as low as 0.12 (after composite modification), and its wear life is more than 5 times that of ordinary engineering plastics.

II. Core Applications

Relying on its characteristics of "high temperature resistance, high strength, corrosion resistance, and easy processing", PEEK is widely used in high-end manufacturing fields. The main segmented markets are as follows:

1. Medical and Health (25% Share)

• Implants: 3D-printed skull prostheses, intervertebral fusion cages, artificial joints, etc. Their bone integration strength is 40% higher than that of titanium alloy, and there is no risk of metal ion release.
• Surgical Instruments: Handles of high-temperature sterilization instruments and dental implant abutments, which can withstand repeated high-pressure steam sterilization.
• Medical Equipment: MRI-compatible stents and dialyzer seals, avoiding metal interference with imaging examinations.

2. Aerospace (20% Share)

• Structural Components: Aircraft engine nacelle doors, seat frames, landing gear components. They reduce weight by 20%~30% while improving corrosion resistance.
• Electronic Components: Satellite solar wing substrates and high-frequency connectors, which work stably in extreme temperatures of -200~260°C.

3. New Energy Vehicles (18% Share)

• Power System: Motor power module covers and battery pack sealing rings (e.g., the exclusive supplier for CATL's 4680 batteries), which can withstand electrolyte corrosion and high temperatures.
• Lightweight Components: Tesla's Optimus humanoid robot joints and bearings adopt PEEK, reducing the overall weight of the robot by 10 kg and increasing the movement speed by 30%.

4. Industrial Machinery (22% Share)

• Wear-Resistant Components: High-pressure pump sealing rings and gearbox bearings. Their service life is 2 times longer than that of metal components under non-lubricated conditions.
• Chemical Equipment: Reactor liners and ultra-pure medium delivery pipelines, which can resist the erosion of strong acids and alkalis.

5. Electronic Information (10% Share)

• Semiconductors: Wafer carriers and chip test boxes. The processed micro-holes have no burrs, and the dimensional stability reaches ±0.01 mm.
• 5G/6G: High-frequency radomes and printed circuit boards. Their dielectric loss is as low as 0.002, meeting the requirements of high-speed signal transmission.

6. Emerging Fields

• Humanoid Robots: A single robot requires 6~10 kg of PEEK materials, which are used in joint modules and transmission parts to replace metals for lightweight and fatigue resistance.
• 3D Printing: Customized components (such as aerospace engine stator casings) are printed by selective laser sintering (SLS) technology.