High-Temperature Electrical Coatings
Coatings are critical to system reliability in high-temperature and electrically demanding environments. Yet they are often the first materials to fail, breaking down under thermal load, electrical stress, or chemical exposure.
Conventional polymers such as epoxies and polyimides eventually soften, crack, or lose their insulating properties over time. Celazole® PBI offers a solution engineered for these extremes.
Thanks to its unique molecular structure and exceptional thermal properties, PBI coatings deliver stable protection where others degrade. Whether applied as a pure film or blended for processing flexibility, PBI maintains structural and electrical integrity under harsh conditions.
Note: PBI is hygroscopic, so dielectric performance is best in dry electrical environments.
Why Traditional Electrical Coatings Fail
Most conventional coatings are not designed to operate under combined thermal, electrical, and chemical stress.
- Epoxies can crack or degrade during thermal cycling
- Polyimides may lose dielectric strength over time
- Standard coatings struggle under high voltage and elevated temperatures
As systems push to higher performance, these limitations become increasingly costly.
Key Advantages of PBI Coatings
- Exceptional thermal stability, with a glass transition temperature of 427 °C
- Outstanding dielectric performance under high voltage and temperature
- Superior chemical resistance to solvents, hydrocarbons, and oxidation
- Strong mechanical durability to resist cracking and delamination
- Flexible processing options including spray, dip, and film coatings
Hybrid Coating Systems: Expanding Performance
Researchers have developed hybrid systems combining PBI with acrylates, epoxies, and polyvinyl butyral (PVB) to enhance processability and performance.
- PBI-acrylate systems enable UV-curable coatings with strong dielectric performance
- PBI-PVB blends provide durable protective films for electronics
- PBI-epoxy systems produce high-temperature varnishes for electrical components
Electrical Insulation and Protection Performance
PBI coatings perform exceptionally in high-voltage environments where insulation failure is not acceptable.
In electric motor applications, PBI coatings reduced partial discharge and extended insulation lifespan at voltages above 600 V and temperatures near 220 °C.
They also help:
- Suppress electrical arcing
- Reduce corona degradation
- Maintain dielectric integrity across voltage ranges
Processing Flexibility and Film-Casting
Celazole® PBI is solution-processable and can be applied using multiple methods:
- Spray and dip coating for complex geometries
- Thermal curing or UV crosslinking
- Film-casting for multilayer systems
- Lamination into high-temperature assemblies
Durable Adhesive Films and Functional Layers
PBI is widely used in adhesive systems and functional layers where long-term performance is critical.
It helps:
- Maintain adhesion above 200 °C
- Reduce interfacial stress between materials
- Provide dielectric isolation in electronics
PBI vs Traditional Electrical Coatings
| Property | PBI | Epoxy | Polyimide |
|---|---|---|---|
| Thermal Stability | Excellent | Moderate | High |
| Dielectric Stability | High | Moderate | Moderate |
| Durability | High | Moderate | Moderate |
| Best Use Case | Extreme environments | General coatings | Flexible electronics |
A Proven Solution for Demanding Designs
PBI Performance offers polybenzimidazole (PBI) in solution form as a versatile platform for high-temperature coatings.
It can be applied directly or used as a formulation base for custom coating systems designed for extreme environments.
From magnet wire insulation to circuit protection and structural adhesives, PBI enables engineers to design for performance beyond conventional limits.
Contact PBI Performance Products to discuss formulations or request technical data.
Frequently Asked Questions
What makes PBI coatings different?
PBI coatings provide superior thermal stability, chemical resistance, and dielectric performance compared to conventional coatings.
Can PBI coatings handle extreme heat?
Yes, PBI coatings maintain performance at temperatures exceeding 400 °C.
Where are PBI coatings used?
They are used in electric motors, aerospace systems, and high-temperature electronics.
Are PBI coatings electrically insulating?
Yes, PBI offers strong dielectric performance in demanding electrical environments.