Phenyl vinyl silicone, usually referred to as phenyl silicone rubber, is a product obtained by introducing methylphenyl siloxane chain segments or diphenyl siloxane chain segments into the molecular chain of silicone rubber. The properties of this silicone are largely affected by the phenyl content in its molecular structure. The crystallization behavior of phenyl vinyl silicone at low temperature can be analyzed from the following aspects:

1. The influence of phenyl on crystallization behavior
Reduction of crystallization temperature:
Due to the introduction of phenyl in the molecular structure of silicone rubber, this large-volume group destroys the regularity of the siloxane molecular structure, thereby reducing the crystallization temperature of the polymer. This characteristic enables phenyl silicone rubber to maintain good elasticity at low temperatures and is not prone to crystallization and hardening.
Changes in crystallinity:
The introduction of phenyl not only reduces the crystallization temperature, but also may affect the crystallinity of silicone rubber. Specifically, with the increase of phenyl content, the crystallinity of silicone rubber may further decrease, thereby improving its cold resistance and elasticity.

2. Specific performance at low temperature
Elasticity retention:
In low temperature environments, phenyl vinyl silicone can maintain good elasticity and is not prone to embrittlement or hardening. This makes it particularly suitable for occasions that need to work under low temperature conditions, such as aerospace, military industry and other fields.
Crystal form:
There may be a lack of direct experimental research data on the specific crystal form of phenyl vinyl silicone at low temperature. However, it can be speculated that due to its lower crystallization temperature and higher elasticity, phenyl silicone rubber may exist in a looser crystal form at low temperature, or no obvious crystallization phenomenon may occur at all.

3. Application Examples
Phenyl vinyl silicone is widely used in many fields due to its excellent low temperature resistance, such as:

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.
Medical industry: used to make artificial organs, heart stents and other medical devices.
Petrochemical industry: various types of high temperature, low temperature, chemical corrosion resistant pumps, valves, oil tanks and other equipment sealing products.
Aviation industry: fuel oil and lubricating oil resistant seals and contact parts on aircraft.

The crystallization behavior of phenyl vinyl silicone rubber at low temperatures is mainly manifested in the decrease of crystallization temperature and the change of crystallinity. These changes together give phenyl silicone rubber excellent low temperature resistance. However, its specific crystallization morphology and mechanism at low temperatures still need further experimental research and theoretical analysis to reveal.