RI. Basic Properties of Phenyl Silicone
Phenyl silicone is a specially modified silicone rubber material. By introducing phenyl groups into the siloxane backbone, it significantly improves the performance limitations of ordinary silicone rubber. Based on the phenyl content, it can be divided into three categories: low phenyl (5-10%), medium phenyl (10-20%), and high phenyl (above 30%).

1. Temperature Resistance
Low-Temperature Performance: Low-phenyl silicone maintains elasticity at temperatures between -70°C and -100°C, offering the best low-temperature performance among all rubbers.

High-Temperature Performance: High-phenyl silicone can withstand temperatures up to 350°C, meeting the high-temperature requirements of applications such as new energy vehicles and AI server cooling.
Wide Temperature Stability: Maintains excellent elasticity from -60°C to 250°C and can withstand transient temperatures exceeding 300°C.

2. Chemical Resistance: Excellent stability against water, air, oxygen, various metals, and plastics. Excellent radiation resistance, particularly suitable for radiation environments such as the nuclear industry. Excellent oil resistance and superior corrosion resistance compared to ordinary rubber. Relatively weak resistance to strong acids and alkalis; selection should be tailored to the specific medium.

3. Mechanical Properties
Tensile Strength: 5-10 MPa
Elongation at Break: >150%
Elastic Modulus: >4 MPa
Heat Deflection Temperature: >170°C

II. Operating Requirements for Chemical Equipment Seals
Chemical equipment seals place special demands on materials, primarily considering the following factors:

1. Temperature and Pressure Conditions
Common Operating Temperature Range: -40°C to 300°C
Pressure Requirement: ≤4.0 MPa (Double-End Mechanical Seals)
Special Operating Conditions: Exhaust temperatures in some reactors can reach over 200°C

2. Media Characteristics
Corrosive Media: Corrosion-Resistant Materials Such as Silicon Carbide or Ceramic Required
Media Containing Solid Particles: Carbide End Faces and a Flushing System Required
High-Viscosity Materials: A Large Spring Compensation Structure is Recommended

III. Performance Comparison of Phenyl Silicone with Other Sealing Materials
1. Comparison with Ordinary Silicone
Performance Indicators: Phenyl Silicone
Ordinary Silicone
Low-Temperature Resistance: -73°C to -55°C
High-Temperature Resistance: 350°C to 200°C
Radiation Resistance: Excellent General
Compression Set Small Large

2. Comparison with Fluororubber
Performance Index Phenyl Silicone Fluororubber
Temperature Range -70-350°C -20-250°C
Chemical Resistance Good (Except Strong Acids and Alkalis) Excellent
Mechanical Strength 5-10MPa >20MPa
Elongation at Break >150% 100-300%

V. Phenyl Silicone Selection Recommendations
1. Key Selection Considerations
Media Characteristics: Determine whether the media contains strong acids, bases, or organic solvents.
Temperature Range: Select a product with the appropriate phenyl content based on the operating temperature.
Pressure Conditions: Consider material compression set for high-pressure applications.
Dynamic/Static: Consider friction coefficient and wear resistance for dynamic seals.
Industry Standards: Meet specific industry certification requirements.

2. Phenyl Content Selection Guide
Phenyl Content Applicable Applications Temperature Range Features
5-10% Ultra-low temperature environments -100-200°C Optimal low-temperature performance
10-20% Medium temperature environments Self-extinguishing properties at -70~250℃
High temperature/radiation environments: over 30%
Optimal radiation resistance at -60~350℃

VI. Conclusions and Recommendations
Phenyl silicone rubber offers unique advantages in chemical equipment sealing due to its excellent high and low temperature resistance, radiation resistance, and chemical stability. Phenyl silicone rubber is an ideal choice for chemical equipment sealing applications that require wide temperature ranges, radiation resistance, or special media. When selecting a seal, consider factors such as media characteristics, temperature and pressure conditions, and sealing configuration, prioritizing products that meet industry standards. For extreme operating conditions, actual operating tests are recommended to verify seal reliability.