Phenyl silicone rubber, with its excellent low-temperature resistance (maintaining elasticity from -100℃ to -110℃) and wide temperature range stability (-100℃ to 400℃), has become a key material in the field of automotive low-temperature components, especially suitable for automotive applications in extremely cold regions and under extreme climate conditions.
I. Core Applications of Phenyl Silicone Rubber in Automotive Low-Temperature Components
1. Sealing Systems
Door/Window Seals: Maintains flexibility in extremely cold environments below -40℃, avoiding the embrittlement and cracking problems of traditional rubber seals, ensuring tight door closure and preventing wind noise and water ingress.
Engine Compartment Seals: Used for engine compartment accessories resistant to -40℃, effectively preventing sealing failure and oil and gas leakage caused by low temperatures.
Special Sealing Applications: Low-phenyl silicone rubber retains its flexibility and elasticity at -100℃, making it particularly suitable for the sealing needs of automobiles in extremely cold regions.
2. Powertrain System
Timing Belts: Maintains flexibility in low-temperature environments, avoiding sliding friction and sharp noises caused by rubber hardening during cold starts, especially suitable for vehicles in extremely cold regions.
Oil Seal Components: Maintains good sealing performance under low-temperature conditions, preventing engine oil leakage, and has advantages over traditional nitrile rubber oil seals in low-temperature performance.
3. Exhaust System
High-Temperature Pipe Connectors: The high-temperature resistance of phenyl silicone rubber (up to 400℃) makes it perform excellently in exhaust systems, maintaining stable performance even under extreme temperature changes such as rapid temperature increases after cold starts.
4. Electronic Systems
Electronic Component Sealing: Used for sealing and protecting precision electronic components such as automotive electronic control units (ECUs) and sensors. Its excellent electrical insulation properties and low-temperature resistance ensure the stable operation of electronic equipment in cold environments.
Wire Harness Protection: As a low-temperature resistant insulation material, it protects automotive wire harnesses from damage under extremely cold conditions.
5. New Energy Vehicle Applications
Battery Sealing: In new energy vehicle battery systems, phenyl silicone rubber is used for battery pack sealing, ensuring the safety and sealing of the battery system in low-temperature environments.
Motor Bearing Seals: Used for seals in new energy vehicle motor bearings, its low-temperature resistance ensures the normal operation of the motor in cold environments. II. Advantages of Phenyl Silicone Rubber at Low Temperatures
1. Comparison of Low-Temperature Performance
Low-phenyl silicone rubber: Phenyl content 5%-10%, remains elastic at -100℃, and the hardening temperature drops to -115℃.
Medium-phenyl silicone rubber: Possesses excellent cold resistance and self-extinguishing properties.
High-phenyl silicone rubber: Phenyl content above 30%, although its low-temperature performance is slightly lower than low-phenyl products, it has superior radiation resistance and ablation resistance, making it suitable for special environments.
2. Comparison with Other Rubber Materials
Silicone rubber (VMQ): Ordinary silicone rubber has a low-temperature resistance of -55℃, which can reach -73℃ after the introduction of phenyl groups, while phenyl silicone rubber can be further improved to -100℃.
Ethylene propylene diene monomer rubber (EPDM): Low-temperature range of -40℃ to -60℃, lower than phenyl silicone rubber.
Chloroprene rubber (CR): Low-temperature range of -40℃ to -50℃, elasticity gradually lost below -50℃.
Nitrile butadiene rubber (NBR): Poor low-temperature performance, generally around -30℃.

III. Application Advantages and Technical Characteristics
1. Core Performance Advantages
Wide temperature range elasticity retention: Maintains excellent elasticity continuously in the range of -100℃ to +70℃, far superior to traditional rubber materials.
Low compression set: Even under prolonged pressure or heat, it maintains a low compression set rate, ensuring stable sealing performance.
Weather resistance: Long-term resistance to ultraviolet rays, ozone, moisture, and various chemical substances, not prone to aging or deterioration.
Electrical insulation: Possesses excellent electrical insulation properties, suitable for automotive electronic systems.
2. Technical Parameters
Phenyl content: 2.5%-60.0 mol% adjustable, affecting low-temperature performance.
Viscosity range: 2000-100000 mPa.s (25℃), adaptable to different processing needs.
Low-temperature performance: Maintains good elasticity even at -120℃.
Molecular weight: 400,000-800,000, affecting the mechanical properties of the material. IV. Practical Application Cases
1. Vehicle Applications in High-Altitude and Cold Regions
In regions like Northeast and Northwest China, where winter temperatures can drop to -40℃, vehicles using phenyl silicone rubber seals perform exceptionally well, avoiding problems such as door closure issues and abnormal noises caused by traditional seals hardening and cracking at low temperatures.
2. Application of Aerospace Technology
Phenyl silicone rubber technology originating from the aerospace field has been successfully applied to civilian automobiles. For example, the high-purity methylphenyl cyclic compound preparation technology developed by Shandong University has been applied to equipment such as the "Tianhe Core Module," and related technologies are gradually being applied to high-end automotive sealing systems.
3. New Energy Vehicle Applications
With the development of new energy vehicles, the application of phenyl silicone rubber in battery systems and motor systems is becoming increasingly widespread. Its low-temperature resistance ensures the reliable operation of new energy vehicles in cold regions.

V. Application Suggestions
Vehicles in high-altitude and cold regions: It is recommended to prioritize low-phenyl silicone rubber seals to ensure sealing performance in environments below -40℃.
Engine peripheral components: Medium-phenyl silicone rubber can be considered, balancing oil resistance and low-temperature performance.
Electronic systems: High-purity phenyl silicone rubber is recommended to ensure electrical insulation performance and low-temperature stability.
New energy vehicles: It is recommended to use high-phenyl silicone rubber in battery systems and motor systems to obtain better radiation resistance and ablation resistance.
The application of phenyl silicone rubber in automotive low-temperature components not only improves the reliability and comfort of vehicles in cold environments but also promotes the innovation of automotive sealing technology. With the continuous progress of material science, the application prospects of phenyl silicone rubber will be even broader, especially in the fields of new energy vehicles and intelligent driving.