The influence of molecular structure and phenyl content:
The introduction of phenyl functional groups into the molecular structure of phenyl silicone oil can reduce the flexibility of the molecular chain and hinder the movement between molecular chains. When the phenyl content increases, the creep and irreversible elongation of silicone oil at high temperature are reduced, but the ability to recover deformation decreases, and the irreversible deformation increases.
For example, the creep and irreversible deformation of methylphenyl silicone rubber at high temperature decrease due to the increase of phenyl content, but the deformation recovery ability weakens after the external force is removed, and the irreversible deformation increases.

Performance under high temperature environment:
Under high temperature environment, the activity of phenyl silicone oil chain segments increases, and it is more likely to move and slip between molecular chains, resulting in an increase in creep. However, the presence of phenyl hinders the movement of molecular chains and reduces irreversible deformation, and may show a better creep recovery rate in short-term high-temperature tests.
Considerations in practical applications:
Phenyl silicone oil is often used in scenarios such as high-temperature resistant lubricants and heat transfer oils. Its creep recovery rate at high temperature needs to be evaluated in combination with specific application conditions. For example, in electrical and electronic equipment, phenyl silicone oil needs to remain stable above 250°C, at which point the creep recovery rate may be improved by optimizing the phenyl content.