Polysulfide Rubber
What is Polysulfide Rubber?
Polysulfide rubber is a specialty synthetic elastomer known for its exceptional resistance to fuels, oils, solvents, and extreme weather conditions. This unique material offers outstanding thermal stability and low-temperature flexibility, making it ideal for demanding industrial applications.
Key Technical Specifications
Physical Properties
- Density: 1.34-1.42 g/cm³
- Tensile Strength: 4.0-7.0 MPa
- Elongation at Break: 200-400%
- Hardness (Shore A): 40-90
- Compression Set: 15-30%
Thermal Properties
- Operating Temperature: -60°C to +120°C
- Glass Transition Temperature: -65°C to -40°C
- Thermal Conductivity: 0.25 W/m·K
- Coefficient of Thermal Expansion: 180-220 × 10⁻⁶/K
| Property | Test Method | Value Range |
|---|---|---|
| Fuel Resistance (ASTM #1 Oil) | ASTM D471 | Volume swell < 10% after 70h at 100°C |
| Weather Resistance | ASTM G154 | No cracking after 2000h UV exposure |
| Low Temperature Flexibility | ASTM D2137 | Passes at -55°C |
| Chemical Resistance | ASTM D543 | Excellent against acids, alkalis, and solvents |
Polysulfide Rubber FAQ
What are the primary applications of polysulfide rubber?
Polysulfide rubber is extensively used in aerospace fuel tank sealants, automotive fuel system components, chemical processing equipment, marine applications, and construction sealants. Its excellent fuel and chemical resistance make it particularly valuable for gaskets, diaphragms, and sealing systems in harsh environments where other elastomers would degrade.
Manufacturing Process
Our polysulfide rubber is produced through a carefully controlled process:
- Polymerization of sodium polysulfide with organic dichlorides
- Washing and purification to remove byproducts
- Compounding with reinforcing fillers and additives
- Vulcanization using metal oxides or peroxides
- Quality testing and certification
Comparative Performance Data
| Property | Polysulfide Rubber | Nitrile Rubber | EPDM |
|---|---|---|---|
| Fuel Resistance | Excellent | Good | Poor |
| Low Temp Flexibility | Excellent | Good | Fair |
| Chemical Resistance | Excellent | Good | Fair |
| Maximum Service Temp | 120°C | 100°C | 150°C |
Polysulfide Rubber FAQ
How does polysulfide rubber compare to silicone for sealing applications?
While silicone offers higher temperature resistance (up to 230°C), polysulfide rubber provides superior fuel and oil resistance. Polysulfide maintains better compression set characteristics in long-term sealing applications and exhibits greater resistance to permeation by hydrocarbon fluids. For fuel systems and chemical exposure, polysulfide is often the preferred choice despite its lower maximum service temperature.
Custom Formulation Options
We offer specialized polysulfide rubber formulations with enhanced properties:
- High-Temperature Grade: Extended service up to 140°C with modified curing systems
- Low-Modulus Version: Softer compounds for improved sealing at low pressures
- Conductive Formulations: Carbon-filled grades for EMI/RFI shielding
- Colored Compounds: Custom pigmented versions for identification purposes
- FDA-Compliant: Formulations meeting 21 CFR 175.300 for food contact
Polysulfide Rubber FAQ
What is the shelf life of polysulfide rubber products?
Properly stored polysulfide rubber components typically maintain their properties for 24-36 months from manufacture date. The shelf life can be maximized by storing materials in their original packaging at temperatures between 10-25°C (50-77°F), away from direct sunlight and moisture. For liquid polysulfide sealants and adhesives, the shelf life is typically 12 months unopened, or 6 months after opening when stored in tightly sealed containers.
Quality Assurance
Our polysulfide rubber products meet rigorous quality standards:
- ISO 9001:2015 certified manufacturing
- ASTM D2000 classification testing
- Batch traceability throughout production
- Third-party laboratory verification available
- Material certifications upon request (RoHS, REACH compliant)