I. Phenyl Silicone's Cold Resistance
Phenyl silicone is a specialty rubber material made by introducing phenylsiloxane chains into polysiloxane side groups. Its cold resistance significantly outperforms ordinary silicone rubber:

Low-Temperature Performance Parameters:
Minimum operating temperature can reach below -100°C, with some models maintaining flexural elasticity at -120°C.
Curing temperature can reach -115°C (low-phenyl silicone rubber).
Long-term operating temperature range is -60°C to 250°C.
Glass transition temperature is below -100°C.

Cold Resistance Mechanism:
The introduction of phenyl groups disrupts the regularity of the dimethylsiloxane structure, significantly lowering the polymer's crystallization temperature. This disruption of molecular chain regularity reduces the crystallization temperature by 9°C compared to ordinary silicone rubber, reaching -115°C. The compression cold resistance coefficient remains above 0.85 at -70°C.

Cold Resistance Characteristics of Different Types of Phenyl Silicone:
Low-phenyl silicone rubber (benzene content 5-10%): It offers optimal low-temperature resistance and maintains elasticity at -100°C.
Medium-phenyl silicone rubber: Self-extinguishing, but slightly less cold-resistant than low-phenyl silicone rubber.
High-phenyl silicone rubber: Its primary advantage lies in radiation resistance.

II. Advantages of Phenyl Silicone in Low-Temperature Environments
Phenyl silicone rubber exhibits numerous advantages in low-temperature environments:
Physical Performance Advantages:
Maintains excellent flexibility at extremely low temperatures (where other materials would harden and crack).
Low compression set and a wide operating temperature range.
Stable dynamic mechanical properties, effectively suppressing the adverse effects of vibration.
Environmental Adaptability Advantages:
Excellent thermal cycling resistance, capable of withstanding extreme temperature fluctuations such as those in space.
Excellent ozone resistance.
Good weathering and aging resistance.
Functional Performance Advantages:
Excellent electrical insulation properties, ideal for sealing and insulating electronic components.
Physiologically inert, suitable for medical applications.
Outstanding radiation resistance (high-phenyl silicone rubber can withstand temperatures up to 2.58 × 10°C/kg). Gamma-ray Radiation)

III. Practical Applications of Phenyl Silicone in Low-Temperature Environments
Phenyl silicone, with its excellent cold resistance, plays a key role in a variety of low-temperature applications:

Aerospace:
Aircraft fuel and lubricant-resistant seals and contacts (O-rings, gaskets, sealing rings); Hydraulic system fluid delivery bellows and sensor materials; Spacecraft components capable of withstanding extreme temperature fluctuations in space

Automotive:
Automotive parts for high-altitude cold regions (sealing rings, oil seals, diaphragms); Engine seals and door seals (for use in -70°C to -100°C environments); Door, window, and trunk lid seals for specialized vehicles

Electronics and Electrical:
High-temperature cables and cable sheaths for cryogenic environments
Electrical insulation and electronic equipment seals

Sealing materials for biomedical cryogenic storage equipment
Military and Energy:

Seals for military aircraft hydraulic systems
Irradiation-resistant seals and tubing for nuclear power plants
Ablation-resistant components for reactor facilities

Other Special Applications:
Sealing materials for polar research equipment
Seals for superconducting equipment in cryogenic environments
Sealing solutions for liquefied natural gas (LNG) equipment

IV. Comparison of Phenyl Silicone Performance in Cryogenic Environments
Compared to other materials, phenyl silicone performs particularly well in cryogenic environments:

Performance Indicators                Phenyl silicone rubber,     ordinary silicone rubber,              other rubber materials
Minimum operating temperature:             -100°C                          -55°C                                     -40°C
Curing temperature:                               -115°C                          -60°C                                     -30°C
Compression set:                                      Small                          Medium                                   Large
Heat cycle resistance:                              Excellent                       Good                                        Fair
Electrical insulation:                                Excellent                        Good                                        Fair

V. Summary and Outlook
Phenyl silicone achieves exceptional cold resistance through molecular structural design. Its lowest operating temperature can reach below -100°C, maintaining excellent elastic and mechanical properties even in extremely low-temperature environments. This material offers irreplaceable advantages in demanding low-temperature applications such as aerospace, automotive, and electronics.

With technological advancements, the demand for material cold resistance will continue to increase. Phenyl silicone is expected to play a vital role in emerging low-temperature applications such as superconducting technology, deep space exploration, and polar exploration. Future research can further optimize the phenyl content and distribution to balance cold resistance with other performance indicators and expand its application.