ABCs of Polyketone

The ABCs of Polyketone: An Introduction for Everyone Interested in Polymers & Plastics

What is Polyketone?

Polyketone (PK) is a next-generation engineering thermoplastic, commercialized by Hyosung under the brand name Poketone. It is an aliphatic polymer created by polymerizing carbon monoxide (CO) with olefins such as ethylene and propylene. This unique structure gives Polyketone a remarkable balance of mechanical, chemical, and environmental properties.

Structure and Types

Polyketone’s backbone alternates between carbonyl (C=O) groups and methylene (–CH₂–) units, resulting in a semi-crystalline structure. There are two main types:

• Copolymer Polyketone: Made from CO and ethylene. It features high crystallinity and excellent mechanical and thermal stability.

• Terpolymer Polyketone: Made from CO, ethylene, and propylene. The addition of propylene units enhances processability, making it easier to use in injection molding and extrusion.

Key Properties

Polyketone stands out for its:

• High Mechanical Strength & Toughness: Superior impact resistance and resilience, even compared to PA6.6 and POM.

• Outstanding Chemical Resistance: Withstands acids, bases, fuels, and solvents, making it suitable for demanding environments.

• Low Water Absorption: Much lower than polyamides, ensuring dimensional stability and consistent performance.

• Excellent Wear & Friction Properties: Ideal for tribological applications like gears and bushings.

• Thermal Stability: High melting point (up to 220°C) and heat deflection temperature (up to 210°C).

• Barrier Properties: Excellent resistance to gas and liquid permeation.

• Environmental Safety: Free from hazardous substances, with low VOC emissions and food contact approvals (FDA, NSF, KFDA).

Processing

Polyketone is highly processable using standard thermoplastic techniques:

• Injection Molding: Fast crystallization allows for short cycle times and high productivity.

• Extrusion: Suitable for pipes, films, and monofilaments.

• Compounding: Can be reinforced with glass fibers, minerals, or modified for tribological or food contact applications.

Typical Applications

Thanks to its unique property profile, Poketone is used in:

• Automotive: Fuel lines, connectors, gears, bushings, and EV components.

• Industrial: Tubing liners, cable ties, pump housings, and water meters.

• Consumer Goods: Food conveyor belts, drinking water pipes, toys, and cosmetic packaging.

• Electrical/Electronics: Connectors and housing covers.

• 3D Printing: Powders for SLS, offering high impact and chemical resistance.

Sustainability

Polyketone is designed with sustainability in mind:

• Low Carbon Footprint: Lower CO₂ emissions in production compared to PA6, PA66, and POM.

• Bio-based Options: Up to 46% bio-ethylene content available.

• Recyclability: Chemically recyclable and suitable for post-industrial recycling.

Summary Table: Poketone vs. Other Engineering Plastics