Phenyl raw rubber (phenyl silicone rubber) possesses excellent chemical resistance and sealing performance, making it particularly suitable for sealing applications in extreme environments. The phenyl group in its molecular structure endows it with superior chemical stability and temperature resistance compared to ordinary silicone rubber.

I. Chemical Resistance of Phenyl Raw Rubber
Broad Chemical Stability
Phenyl silicone rubber exhibits excellent resistance to a variety of chemicals, including excellent resistance to aromatic hydrocarbons, oxidants, and salt media.

It also demonstrates good resistance to acid and alkali corrosion, maintaining stable performance even in highly corrosive environments such as petrochemical plants.

Performance in Specific Media

In IRM-901 standard oil and aviation kerosene RP-3, the media resistance of phenyl silicone rubber is comparable to that of ordinary silicone rubber, unaffected by increasing phenyl content.

However, in phosphate ester hydraulic oil Skydrol LD-4, its media resistance significantly decreases with increasing phenyl content, indicating that the phenyl content must be carefully selected in specific chemical environments.

Relationship between Phenyl Content and Chemical Resistance
As the phenyl content increases, the rigidity of the silicone rubber molecular chain increases, improving chemical corrosion resistance, but simultaneously decreasing low-temperature resistance.

High-phenyl silicone rubber (phenyl content >30%) performs particularly well in highly corrosive and high-radiation environments, making it suitable for special applications such as nuclear power plants.

II. Sealing Performance Characteristics of Phenyl Raw Rubber
Wide Temperature Range Sealing Capability
Phenyl silicone rubber has an extremely wide operating temperature range: low-phenyl type can operate from -100℃ to 150℃, medium-phenyl type has an ablation temperature >280℃, and high-phenyl type has an ablation temperature >300℃.

Low-phenyl silicone rubber maintains good elasticity even at extreme low temperatures of -70℃ to -100℃, making it the rubber with the best low-temperature performance.

Sealing Performance Advantages
Low compression set characteristics allow it to maintain shape and dimensional stability under prolonged pressure or heat, making it suitable for applications with extremely high sealing requirements.

Excellent electrical insulation properties make it an ideal sealing and insulation material for electronic and electrical equipment.

Sealing Performance in Special Environments

In the aerospace field, phenyl silicone rubber maintains stable sealing performance under extreme temperature variations ranging from -110℃ to 400℃, effectively coping with the drastic temperature changes caused by alternating direct sunlight and Earth's shadow during satellite orbit operation.

High-phenyl silicone rubber exhibits excellent radiation resistance, withstanding 2.58×10⁴ C/kg gamma-ray radiation, making it suitable for sealing in high-radiation environments such as nuclear power plants.

III. Phenyl Content and Sealing Application Selection
Low-phenyl silicone rubber (5-10% phenyl content): Optimal low-temperature resistance, curing temperature as low as -115℃, maintaining flexibility at -100℃.

Suitable for low-temperature environments such as automotive parts and cryogenic equipment sealing in extremely cold regions.

Medium-phenyl silicone rubber (15-25% phenyl content): Combines good high-temperature resistance and flame retardancy, self-extinguishing in case of fire.

Suitable for medium-temperature and fire-resistant applications such as automotive engine seals, fire-resistant cables, and fireproof seals.

High-phenyl silicone rubber (phenyl content above 30%) offers excellent radiation and ablation resistance, making it suitable for extreme environments such as nuclear power plant sealing and space sealing.

The radiation-resistant phenyl silicone rubber used in the construction of the Shidaowan Nuclear Power Plant is a typical application example.

IV. Typical Application Areas
Aerospace: Sealing rings, gaskets, pipes, and rods for aircraft, rockets, and satellites, designed to withstand the harsh environment of space.
Automotive Industry: Engine seals, door seals, oil seals, etc., designed to withstand the high-temperature environment surrounding the engine.
Nuclear Power: Nuclear reactor seals, radiation-resistant coatings, addressing the issue of domestic production and overcoming bottlenecks.

Electronics and Electrical Appliances: Sealing and insulating electronic components to prevent moisture and dust ingress, protecting the normal operation of electronic components.

Military Industry: Hydraulic bellows for military aircraft, door/window/rear cover seals for special vehicles, and other harsh environment applications.
Choosing the appropriate phenyl content is crucial for specific applications: choose low-phenyl type for low-temperature resistance, medium-phenyl type for high-temperature resistance and fire resistance, and high-phenyl type for radiation resistance.