What is PEEK?
PEEK is a standard and universal abbreviation in the polymer materials field, referring essentially to polyether ether ketone—a high-performance thermoplastic engineering plastic whose molecular backbone contains repeating ether bond and ketone bond structures. Hailed as the "king of ultra-high-performance engineering plastics", it is widely used in cutting-edge fields such as aerospace and high-end medical care, thanks to its exceptional properties including high temperature resistance, chemical corrosion resistance and high strength.
Core Properties and Production Process of PEEK
Raw Material Sources
The core raw materials are 4,4'-difluorobenzophenone and hydroquinone, both of which are petroleum-based fine chemical products. The synthesis process imposes extremely high requirements on raw material purity. At present, bio-based monomer technology has not yet achieved a breakthrough, and large-scale bio-based production of PEEK has not been realized.
Production Process
The mainstream industrial process is nucleophilic substitution polycondensation. Under the conditions of high temperature, inert gas protection and alkali metal carbonate catalysis, 4,4'-difluorobenzophenone and hydroquinone undergo a polycondensation reaction to generate high-molecular-weight PEEK polymers. The polymerized product requires precision pelletizing, and high-temperature extrusion or injection molding (processing temperature needs to reach 360–400℃). For some high-end products, carbon fiber or glass fiber reinforcement modification is also applied to further enhance mechanical properties.
Key Properties
Its core advantage lies in a well-balanced combination of all-round ultra-high performance:
- It has extremely strong high temperature resistance, with a heat deflection temperature of approximately 315℃, enabling long-term use at 250℃ and instantaneous resistance to temperatures exceeding 500℃.
- Its chemical corrosion resistance is comparable to that of metals; it can resist erosion by various media such as acids, alkalis, organic solvents and fuel oil, except for strong oxidizing media like concentrated sulfuric acid.
- It boasts excellent mechanical strength, with a tensile strength of 90–100MPa; its impact resistance and fatigue resistance far exceed those of ordinary engineering plastics.
- It also exhibits outstanding electrical insulation, flame retardancy and biocompatibility (medical-grade PEEK can be implanted into the human body).
Its main drawbacks are its high cost (dozens of times that of ABS) and high processing difficulty, which impose stringent requirements on equipment and processes.
Application Scenarios
PEEK focuses on high-end and extreme working condition fields, covering aerospace (aircraft engine components, spacecraft structural parts), high-end medical care (artificial joints, spinal implants, surgical instruments), petrochemical engineering (high-temperature and high-pressure valves, offshore drilling platform components), electronics and semiconductors (wafer carriers, chip testing fixtures) and other industries. It is particularly suitable for replacing metal materials to meet the demands of lightweight design and corrosion resistance.
