Polyacrylate Rubber
Polyacrylate Rubber: A High-Performance Elastomer
Polyacrylate Rubber (ACM) is a specialty synthetic rubber known for its excellent resistance to heat, oil, and ozone. Widely used in automotive and industrial applications, this material offers superior performance in demanding environments.
Key Features of Polyacrylate Rubber:
- Exceptional heat resistance (up to 175°C continuous service)
- Outstanding oil and hydrocarbon fluid resistance
- Good compression set properties
- Excellent ozone and weathering resistance
- Moderate mechanical strength
- Fair low-temperature flexibility
Technical Specifications
| Property | Value | Test Method |
|---|---|---|
| Hardness (Shore A) | 40-90 | ASTM D2240 |
| Tensile Strength | 7-12 MPa | ASTM D412 |
| Elongation at Break | 100-400% | ASTM D412 |
| Compression Set (22hrs @ 150°C) | 15-40% | ASTM D395 |
Applications of Polyacrylate Rubber
Polyacrylate Rubber is particularly suitable for automotive sealing systems, including:
- Engine and transmission seals
- Valve stem seals
- O-rings for high-temperature applications
- Gaskets and hoses
Polyacrylate Rubber FAQ
What temperature range can Polyacrylate Rubber withstand?
Polyacrylate Rubber typically performs well between -20°C to 175°C (-4°F to 347°F). Some specially formulated grades can withstand intermittent exposure up to 200°C (392°F). The material maintains its properties better at high temperatures than many conventional rubbers.
How does Polyacrylate Rubber compare to Nitrile Rubber?
While Nitrile Rubber (NBR) offers better mechanical properties and lower temperature flexibility, Polyacrylate Rubber outperforms NBR in high-temperature applications (above 150°C) and provides superior resistance to oils, especially sulfur-bearing oils. Polyacrylate Rubber also has better ozone and weathering resistance.
Is Polyacrylate Rubber suitable for food contact applications?
Standard Polyacrylate Rubber is not recommended for food contact. However, special FDA-compliant grades are available that meet certain food contact regulations. These require specific compounding and should be verified for compliance with applicable regulations before use.
Material Comparison
| Property | Polyacrylate Rubber | Nitrile Rubber | FKM (Viton) |
|---|---|---|---|
| Max Continuous Temp | 175°C | 120°C | 200°C |
| Oil Resistance | Excellent | Good | Excellent |
| Cost | Medium | Low | High |
Processing Guidelines
- Injection Molding: 160-190°C barrel temperature
- Compression Molding: 150-170°C with 5-15 minute cure time
- Extrusion: Requires careful temperature control to avoid scorching
Polyacrylate Rubber FAQ (continued)
What types of oils is Polyacrylate Rubber most resistant to?
Polyacrylate Rubber shows excellent resistance to sulfur-bearing oils, transmission fluids, and engine oils at elevated temperatures. It performs particularly well against ASTM oils #1 and #3, as well as many synthetic lubricants.
Can Polyacrylate Rubber be bonded to metal?
Yes, Polyacrylate Rubber can be successfully bonded to metal substrates using appropriate adhesives. Primers and specialty bonding agents are typically required for optimal adhesion. Common methods include metal treatment followed by adhesive application before molding.
What is the shelf life of Polyacrylate Rubber compounds?
Uncured Polyacrylate Rubber typically has a shelf life of 6-12 months when stored properly in cool (below 25°C), dry conditions away from direct sunlight and ozone sources. Premixed and ready-to-use compounds may have shorter shelf lives.
Chemical Resistance
| Chemical | Resistance | Notes |
|---|---|---|
| Mineral Oils | Excellent | Best among medium-cost rubbers |
| Water | Fair to Good | Better than NBR at elevated temps |
| Brake Fluids (DOT 3/4) | Good | Limited swelling |
Conclusion
Polyacrylate Rubber offers a unique combination of heat and oil resistance at a competitive price point, making it an excellent choice for demanding automotive and industrial applications. While it has some limitations in low-temperature performance, its advantages in high-temperature environments make it indispensable for many sealing applications.