Phenyl vinyl silicone, namely methylphenyl vinyl silicone rubber (phenyl silicone rubber for short), is widely used in cryogenic seals. The following is a detailed analysis of the application of phenyl vinyl silicone in cryogenic seals:

1. Low temperature performance of phenyl vinyl silicone
Phenyl vinyl silicone destroys the regularity of the dimethylsiloxane structure by introducing methylphenyl siloxane chain segments or diphenyl siloxane chain segments into the molecular chain of vinyl silicone rubber, thereby greatly reducing the crystallization temperature of the polymer and expanding the low temperature application range of the polymer material. Specifically, low phenyl silicone rubber (phenyl content between 6 and 11%) has excellent low temperature resistance, and the brittle temperature of its vulcanized rubber can reach -120°C, which is one of the best low temperature performance rubbers today. This rubber can still maintain good elasticity and sealing performance at low temperatures, which is very suitable for cryogenic seals.

2. Application scenarios of phenyl vinyl silicone in cryogenic seals
Extremely low temperature environments such as liquid nitrogen:
Phenyl vinyl silicone can be used to solve sealing problems in extremely low temperature environments such as liquid nitrogen Dewar flasks. For example, when installing an O-ring on the siphon of a liquid nitrogen dewar, traditional thermosetting rubber may fail because it cannot withstand the extremely low temperature of liquid nitrogen (-196°C). Phenyl vinyl silicone can maintain sealing performance and avoid leakage at such extreme low temperatures.
Aerospace field:
In the aerospace field, many parts need to operate in extremely low temperature environments, such as spacecraft, satellites, etc. Phenyl vinyl silicone is widely used in seals in these fields due to its excellent low temperature resistance to ensure the normal operation of equipment.
Other industrial fields:
In the petrochemical industry, phenyl vinyl silicone can be used for sealing products of various high temperature resistant, low temperature resistant, chemical resistant pumps, valves, oil tanks and other equipment. In the military industry, it is also used in harsh environments that are resistant to low temperature, oil and acid, such as the hydraulic system infusion bellows of military aircraft.

3. Advantages of phenyl vinyl silicone
Excellent low temperature resistance: It can maintain elasticity and sealing performance at extremely low temperatures.
Good mechanical properties: It has high tensile strength and tear resistance.
Excellent chemical resistance: It can resist the erosion of a variety of chemicals.
Wide operating temperature range: usually can be used in the range of -100℃~250℃.
Easy to process and color: easy to process and color according to actual needs.

In summary, phenyl vinyl silicone has broad application prospects and important application value in low-temperature seals. With the continuous advancement of technology and the continuous expansion of applications, it is believed that phenyl vinyl silicone will play an important role in more fields.