Phenyl vinyl silicone (also known as phenyl silicone rubber or methyl phenyl vinyl silicone rubber) has excellent thermal stability at low temperatures, which is mainly due to the phenyl structure introduced into its molecular chain. The following is a detailed analysis of the thermal stability of phenyl vinyl silicone at low temperatures:

1. Low temperature resistance

Extremely low curing temperature: When the phenyl content is 5-10%, the curing temperature of phenyl silicone rubber drops to the lowest value (-115°C), which makes it extremely resistant to low temperatures. Even at a low temperature of -100°C, it can still maintain its flexural elasticity, which is the best low-temperature performance among all rubbers.

Non-crystallization: Phenyl silicone rubber (especially medium phenyl silicone rubber) is a non-crystalline silicone rubber, and its crystalline melting temperature is lower than that of vinyl silicone rubber without phenyl, thereby reducing the crystallization transition at low temperatures and helping to maintain its elasticity.

2. Physical property retention

Elastic recovery: Phenyl vinyl silicone will not undergo permanent changes at ultra-low temperatures. When the temperature returns to room temperature, the rubber can regain its original mechanical properties, thanks to the flexibility and thermal stability of its molecular chain.
Anti-embrittlement: At temperatures where most elastomers become brittle and prone to bending and breaking due to low temperatures, phenyl vinyl silicone can still maintain flexibility and good performance.
3. Application fields
The excellent low-temperature performance of phenyl vinyl silicone makes it widely used in many fields, including but not limited to:

Construction industry: used to make waterproof materials, sound insulation materials, refractory materials, etc.
Automotive industry: various types of vehicle sealing rings, oil seals, diaphragms, catheters, valve linings, etc.
Aerospace: seals and contact parts resistant to fuel oil and lubricating oil on aircraft, such as various O-rings, gaskets, sealing rings, etc.
Military industry: in harsh environments that are resistant to low temperatures, oils, and acids, such as hydraulic system infusion bellows for military aircraft, door and window/back cover sealing strips for special vehicles, etc.

In summary, phenyl vinyl silicone exhibits excellent thermal stability under low temperature conditions, which is mainly due to the introduction of phenyl in its molecular chain and the resulting non-crystallization and excellent low-temperature elasticity. This makes phenyl vinyl silicone one of the ideal materials for working in extremely low temperature environments.