High-ACN HNBR vs. Low-ACN HNBR

Attribute	High-ACN HNBR	Low-ACN HNBR
Acrylonitrile content	Higher	Lower
Resistance to heat aging	Higher	Lower
Resistance to oil and fuel	Higher	Lower
Cost	Higher	Lower

Introduction

Hydrogenated Nitrile Butadiene Rubber (HNBR) is a synthetic polymer that offers excellent resistance to heat, oil, and chemicals. HNBR is commonly used in automotive, aerospace, and industrial applications due to its superior performance in harsh environments. One key factor that differentiates HNBR compounds is the Acrylonitrile (ACN) content, which affects the material's properties. In this article, we will compare the attributes of High-ACN HNBR and Low-ACN HNBR to understand their differences and applications.

High-ACN HNBR

High-ACN HNBR typically contains an ACN content of 36-50%, making it more resistant to oil and fuel compared to Low-ACN HNBR. The higher ACN content provides better resistance to swelling and degradation in contact with petroleum-based fluids, making High-ACN HNBR ideal for applications in the automotive industry, such as seals, gaskets, and O-rings in engines and transmissions. Additionally, High-ACN HNBR offers improved tensile strength and abrasion resistance, making it suitable for dynamic sealing applications where durability is crucial.

Low-ACN HNBR

Low-ACN HNBR, on the other hand, contains an ACN content of 18-34%, making it less resistant to oil and fuel but more flexible and resilient at low temperatures. Low-ACN HNBR is commonly used in applications where flexibility and low-temperature performance are critical, such as seals in refrigeration systems, HVAC components, and outdoor equipment. While Low-ACN HNBR may not offer the same level of oil resistance as High-ACN HNBR, it provides excellent resistance to ozone, weathering, and UV exposure, making it suitable for outdoor applications.

Comparison of Physical Properties

• High-ACN HNBR has a higher tensile strength and abrasion resistance compared to Low-ACN HNBR.
• Low-ACN HNBR is more flexible and resilient at low temperatures than High-ACN HNBR.
• High-ACN HNBR offers better resistance to oil and fuel, while Low-ACN HNBR excels in ozone and weathering resistance.
• Both High-ACN and Low-ACN HNBR exhibit excellent compression set resistance and thermal stability.

Applications

High-ACN HNBR is commonly used in automotive seals, gaskets, and O-rings, where resistance to oil and fuel is essential. Its superior tensile strength and abrasion resistance make it suitable for dynamic sealing applications in engines and transmissions. Low-ACN HNBR, on the other hand, finds applications in refrigeration seals, HVAC components, and outdoor equipment where flexibility and low-temperature performance are critical. Its excellent resistance to ozone and weathering makes it ideal for outdoor applications exposed to harsh environmental conditions.

Conclusion

In conclusion, High-ACN HNBR and Low-ACN HNBR offer distinct advantages based on their ACN content and physical properties. High-ACN HNBR provides superior resistance to oil and fuel, making it ideal for automotive applications, while Low-ACN HNBR offers flexibility and low-temperature performance for refrigeration and outdoor applications. Understanding the differences between High-ACN and Low-ACN HNBR is crucial in selecting the right material for specific applications to ensure optimal performance and durability.