Phenyl components are key additives in compression-resistant silicone rubber formulations, and their mechanism of action and performance impact can be analyzed from multiple dimensions.

Basic Role of the Phenyl Component
The introduction of phenyl significantly improves the high and low temperature resistance of silicone rubber:
Low Temperature Resistance: Ordinary silicone rubber can still function at -55℃, but the introduction of phenyl increases its low temperature resistance to -73℃.
High Temperature Resistance: Phenyl silicone rubber can operate continuously at 180℃, and its instantaneous temperature resistance can reach over 300℃.
Molecular Structure Stability: Phenyl enhances the stability of the siloxane backbone through its steric hindrance and electronic effects.
Mechanism of the Influence of the Phenyl Component on Compression Set Resistance
The phenyl component improves the compression set resistance of silicone rubber through the following mechanisms:

Physical Relaxation Inhibition:
Reducing slippage and rearrangement of rubber molecular chains under pressure
Reducing entropy reduction after stress removal
Restricting irreversible deformation of molecular chains through steric hindrance

Enhanced Chemical Stability:
The introduction of phenyl improves the thermal stability of the siloxane backbone
Reducing thermal rearrangement degradation and side group oxidation of the backbone
Reducing sensitivity to polar substances

Synergistic Effects of the Phenyl Component with Other Components in the Formulation:
Synergistic Component, Synergistic Effect, Performance Improvement, Silica Enhanced mechanical strength and improved resistance to compression set.
Methyl vinyl silicone oil improves processing performance and reduces molecular chain entanglement.
Vulcanizing agents optimize crosslinking density and improve resilience.
The phenyl component can also synergistically optimize the molecular structure with other organic groups in the formulation (such as methyl and vinyl groups) to achieve a performance balance.

Increasing the phenyl content improves temperature resistance but may reduce flexibility.
It is recommended to determine the optimal phenyl content (usually 5-20 mol%) through experiments. Synergistic optimization with vulcanization systems, reinforcing agents, and other components is necessary.
By rationally designing the content of the phenyl component and its ratio with other components, silicone rubber materials with excellent resistance to compression set can be prepared to meet the needs of high-end applications such as aerospace and automotive sealing.