PEEK vs PEKK: Aerospace Polymer Comparison
Published: 2026-06-02
PEEK and PEKK share PAEK chemistry — PEKK has higher ketone/ether ratio → higher Tg (162 vs 143°C), higher melt point. PEKK preferred for aerospace composites (better CAI). PEEK preferred for injection molding (better processability, lower cost)....
PEEK and PEKK share PAEK chemistry — PEKK has higher ketone/ether ratio → higher Tg (162 vs 143°C), higher melt point. PEKK preferred for aerospace composites (better CAI). PEEK preferred for injection molding (better processability, lower cost). PEKK costs ~50-80% more.
Comparison at a Glance
| Tensile Strength | PEEK: 100 vs PEKK: 110 MPa |
|---|---|
| Melting Point | PEEK: 343 vs PEKK: 360°C |
| Shrinkage Rate | PEEK: 1.2 vs PEKK: 0.8% |
| Flexural Modulus | PEEK: 4.1 vs PEKK: 4.5 GPa |
| Hdt | PEEK: 160 vs PEKK: 175°C |
Equivalents & Cross-References
| Equivalent / Alternate | Action |
|---|---|
| Victrex PEEK vs Kepstan PEKK |
Frequently Asked Questions
Which costs more?
PEKK ~50-80% more expensive due to complex monomer synthesis. PEEK is first choice for injection molding. PEKK specified when extra 20°C Tg is required.
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References & Industry Standards
- ASTM International. Standard Specifications for Engineering Plastics & Thermoplastics. astm.org
- UL Prospector. Plastics & Elastomers Material Database. ulprospector.com
- MatWeb. Material Property Data for Engineering Thermoplastics. matweb.com
- ISO 1043. Plastics — Symbols and Abbreviated Terms. iso.org