PEEK
Polyether Ether Ketone
Glass Transition (Tg)
143–145 °C
Melting Point (Tm)
340–343 °C
Density
1.30–1.32 g/cm³
CAS Number
29658-26-2
Recycling Code
♺ 7
Category
High-Performance
Repeat Unit
–[O–C₆H₄–O–C₆H₄–CO–C₆H₄]ₙ–
The repeating unit is the smallest structural fragment whose repetition builds the whole chain. Subscripts show the relative share of each unit in copolymers.
Key Properties
Benchmark high-performance thermoplastic; continuous service to ~250 °C; outstanding chemical resistance (attacked only by concentrated sulphuric acid); inherently flame retardant; radiolucent and biocompatible.
Applications
Spinal cages and implants, aerospace brackets, semiconductor handling, downhole seals.