Published October 2015
Aromatic ketone polymers (AKPs), sometimes referred to as polyaryletherketones (PAEKs) and/or polyetheretherketones, (PEEK) are a family of crystalline thermoplastics characterized by outstanding thermal stability, mechanical properties, and chemical resistance. This family of aromatic polymers mainly includes:
- Polyetheretherketone (PEEKTM)
- Polyetherketone (PEK)
- Polyetherketoneketone (PEKK)
PEEK is the dominant type of AKP, accounting for approximately 85–90% of world production. It has been classified primarily into three main types, including unfilled PEEK, carbon-filled PEEK, and glass-filled PEEK.
The following pie chart shows world consumption of aromatic ketone polymers:
Aromatic ketone polymers have the highest unit price among all high-performance polymers. AKPs exhibit the following characteristics, which are unmatched by other high-performance polymers, and so justify their higher price:
- Excellent high-temperature performance
- Inherent purity
- Excellent combustion-resistance properties
- Unique combination of properties
- Good resistance to virtually all organic chemicals
- Good electrical properties
Because of their unique set of outstanding properties, AKPs have found increasing uses in many critical applications. AKPs’ application benefits include ease of complex component fabrication, reduction in energy consumption, tolerance of harsh environments, improved reliability and operational lifetime, and lighter materials with metal replacement.
On the other hand, AKPs are susceptible to stress-crazing—when mechanically stressed and exposed to organic solvents such as acetone, alcohols, or chlorinated solvents, they form minute cracks with foamlike structures. Stress-crazing dramatically reduces their mechanical and electrical insulation properties and renders them highly penetrable by aqueous electrolytes. AKPs, like all aromatic polymers, also carbonize and form electrically conductive paths under electrical arcing, a phenomenon known as arc-tracking. Therefore, AKPs should not be used in applications that present any possible exposure to organic solvents or electrical arcing.
The world AKP market is dominated largely by the developed markets of the Americas and EMEA. These two regions combined accounted for 70–75% of the global AKP market share in 2014 and 2015. Developing regions, such as China and India, have production capacity, but those capacities are geared more to the export market than to promoting domestic growth.
World consumption of AKPs is expected to grow at an average annual rate of 4–5% during 2015–20. The major end-use sectors for AKPs include transportation (mainly aerospace and automotive), industrial/energy, electrical/electronic, and medical applications (mainly as medical instruments/components and biomaterial implants).