Many engineers and buyers face issues with seals and gaskets that break down in high temperatures or oil-rich environments. I have seen countless cases where using the wrong rubber material led to costly failures and urgent replacement needs.
AEM rubber, also known as ethylene acrylic rubber or Vamac®, is a specialty synthetic elastomer that offers excellent resistance to heat, oils, ozone, and weathering. It is mainly used in automotive, industrial, and sealing applications where durability in harsh environments is critical.
Understanding what AEM rubber is—and what makes it unique—can help you choose the right material for demanding projects. I will share how it’s made, its properties, and where it works best.
How is AEM rubber made and what is its chemical structure?
If you want parts to last under the hood of a car or in heavy machinery, you need to know why AEM rubber performs so well.
AEM rubber is made by copolymerizing ethylene and methyl acrylate, with a small amount of cure-site monomer added. This structure allows for peroxide or amine curing, which provides strong heat and oil resistance.
AEM Rubber Composition Table
| Component | Purpose | Benefit |
|---|---|---|
| Ethylene1 | Base monomer | Flexibility, low-temp performance |
| Methyl Acrylate | Copolymer | Oil, heat, and ozone resistance2 |
| Cure-site Monomer | Crosslinking (curing)3 | Stability, long life |
The resulting rubber has a saturated polymer backbone, which makes it highly resistant to degradation from heat, ozone, and many chemicals.
What are the main properties of AEM rubber?
Choosing the right rubber means knowing how it will perform in real conditions. Many of my customers in automotive and machinery care most about heat, oil, and aging resistance.
AEM rubber combines good flexibility with outstanding resistance to hot oil, weathering, and high temperatures (up to 150°C). It also resists ozone, acids, and water better than many other rubbers.
AEM Rubber Properties Table
| Property | Value/Performance |
|---|---|
| Temperature Range4 | -30°C to +150°C (up to 175°C short-term) |
| Oil Resistance | Excellent |
| Ozone/Weather Resist5 | Excellent |
| Acid/Water Resistance6 | Good |
| Flexibility | Moderate to good |
| Compression Set7 | Low (keeps shape under pressure) |
| Color | Usually black, can be colored |
I always point out that AEM rubber8 does not resist fuels or aromatic solvents as well as FKM (Viton®), but it is a great choice for under-the-hood parts.
Where is AEM rubber used in industry?
When clients ask for a rubber that can handle hot oil and aging, I often suggest AEM. It’s a mainstay in modern vehicles and machinery.
AEM rubber is widely used for automotive hoses, air intake ducts, turbocharger hoses, seals, gaskets, and vibration dampers. Its performance under heat and oil exposure makes it popular in engines, transmissions, and under-hood environments.
AEM Application Table
| Application | Reason for Use |
|---|---|
| Turbocharger Hoses | Heat and oil resistance9 |
| Air Intake Ducts | Ozone and flex resistance |
| Seals & Gaskets | Aging and weathering |
| Vibration Dampers | Flexibility, long life |
| Transmission Parts | Oil and heat resistance10 |
I have supplied AEM rubber parts to automotive suppliers in Europe and Asia. These parts pass demanding durability tests and last for years in service.
How does AEM rubber compare to other specialty rubbers11?
Engineers and buyers often ask, “How does AEM compare with EPDM, ACM, or FKM?” I always look at heat, oil resistance, and cost.
AEM rubber has better oil and heat resistance than EPDM and ACM, but does not match FKM (Viton®) for extreme chemicals and fuels. It provides a balanced solution for applications needing both flexibility and durability.
Rubber Comparison Table
| Property | AEM | EPDM | ACM | FKM (Viton®) |
|---|---|---|---|---|
| Temp. Max (°C) | 150 | 130 | 150 | 250 |
| Oil Resistance | Excellent | Poor | Good | Excellent |
| Ozone Resistance | Excellent | Excellent | Good | Excellent |
| Fuel Resistance12 | Poor | Poor | Poor | Excellent |
| Cost | Medium | Low | Medium | High |
For most automotive air or oil hoses, AEM gives great service at a reasonable price. For exposure to fuels, I always recommend FKM instead.
What are the limitations and handling tips for AEM rubber?
No material is perfect. I remind buyers that knowing the limits of AEM helps avoid expensive failures.
AEM rubber is not suitable for constant contact with fuels, aromatic solvents, or very high temperatures above 175°C. For best results, specify the right cure system, avoid sharp bends, and store parts away from direct sunlight or strong acids.
AEM Rubber Handling Table
| Limitation | Handling Advice |
|---|---|
| Fuel Contact | Avoid, use FKM or NBR instead |
| Extreme Heat | Use only below 175°C |
| Strong Acids/Bases | Check compatibility, test samples |
| Storage | Cool, dry, dark place |
| Installation | Avoid sharp bends, use correct size |
My technical team is always available to help select the best grade and provide samples for testing.
Conclusion
AEM rubber (ethylene acrylic) is a flexible, durable material prized for its heat, oil, and weather resistance. It’s the go-to choice for demanding automotive and industrial applications that need long-term performance.
-
Explore this link to understand how ethylene contributes to rubber's flexibility and performance, crucial for automotive applications. ↩
-
Discover how ozone resistance contributes to the durability of rubber products in harsh environments. ↩
-
Understanding crosslinking is crucial for optimizing rubber performance, especially in applications requiring durability and stability. ↩
-
Understanding AEM rubber's temperature range is crucial for selecting materials in high-performance applications. ↩
-
Explore this resource to discover top materials that excel in ozone and weather resistance, enhancing your rubber applications. ↩
-
Explore this resource to discover various rubber materials with excellent acid and water resistance, enhancing your product choices. ↩
-
Understanding compression set is crucial for evaluating rubber performance in applications where shape retention under pressure is vital. ↩
-
Explore the advantages of AEM rubber for automotive parts, including its heat and oil resistance. ↩
-
Learn why oil resistance is vital for rubber used in automotive and machinery applications. ↩
-
Understanding heat resistance is crucial for selecting the right rubber for high-temperature applications. ↩
-
Explore various specialty rubbers and their applications to make informed material choices. ↩
-
Explore this link to understand how various rubbers, including AEM and FKM, perform against fuels, aiding in material selection. ↩
