Phenyl silicone oil and perfluoropolyether both have unique properties in the field of high-temperature lubrication, but there are significant differences between the two in chemical structure, thermal stability, lubrication mechanism and applicable scenarios. The following is a comparative analysis from the core performance dimension:

1. Thermal stability and decomposition temperature
Phenyl silicone oil:
The introduction of phenyl in the molecular structure significantly improves its thermal stability, and it can be used for a long time above 300℃, and some products can withstand temperatures up to 320℃. Its decomposition temperature is high, but thermal degradation may occur at extremely high temperatures (such as above 400℃), resulting in a decrease in lubrication performance.
Perfluoropolyether:
The molecular chain is composed of carbon-fluorine bonds, with high bond energy and strong chemical inertness. The decomposition temperature is usually above 400℃, and some products can remain stable at 500℃. It is not easy to decompose or volatilize at extremely high temperatures, and is suitable for higher temperature scenarios.

2. Lubrication mechanism and extreme pressure and anti-wear properties
Phenyl silicone oil:
Through the synergistic effect of silicon-oxygen bonds and phenyl, a stable lubricating film is formed at high temperatures. Its lubrication performance is greatly affected by temperature, and the viscosity change may cause insufficient lubrication film thickness at high temperature.
Perfluoropolyether:
It can still maintain a stable molecular structure at high temperature, is not easy to decompose or volatilize, and has excellent lubrication film durability. Its viscosity-temperature curve is flat, and the viscosity change is small at high temperature, which can maintain the lubrication effect for a long time.

3. Lubrication mechanism and friction performance
Phenyl silicone oil:
It forms a lubrication film through the flexibility of the silicon-oxygen bond, but under high temperature and high speed conditions, the wear may be aggravated due to the rupture of the lubrication film.

4. Lubrication performance and extreme pressure and anti-wear performance
Phenyl silicone oil:
Through the synergistic effect of phenyl and silicon-oxygen chains, a stable adsorption film is formed on the metal surface, which has good friction reduction performance. However, under extreme pressure conditions, its lubrication film may rupture due to shear force, resulting in a decrease in anti-wear performance.
Perfluoropolyether:
It can still maintain a low friction coefficient at high temperature, and has strong chemical adsorption on the metal surface, which can form a stable lubrication film. Its extreme pressure and anti-wear performance is better than phenyl silicone oil, especially suitable for high-speed and heavy-load conditions.

5. Chemical stability and compatibility
Phenyl silicone oil:
It is stable to most organic solvents and chemicals, but chemical reactions may occur in strong acid, strong alkali or strong oxidizing environment, resulting in reduced lubrication performance. Its compatibility with certain plastics or rubber materials needs to be verified by experiments.
Perfluoropolyether:
It has extremely strong chemical inertness and shows extremely high tolerance to strong acids, strong alkalis, oxidants and organic solvents, and is suitable for extreme chemical environments. It has good compatibility with metals, plastics and rubber materials and is not prone to corrosion or expansion problems.

6. Lubrication mechanism and applicable scenarios
Phenyl silicone oil:
It forms a lubricating film through the flexibility of the silicon oxygen chain, which is suitable for bearings, gears and seals lubrication at medium and high temperatures (200-320℃). It has good organic compatibility and can be mixed with mineral oil or synthetic oil, which is suitable for scenarios that require both lubrication and sealing.
Perfluoropolyether:
It forms a stable lubricating film through the chemical inertness and low surface tension of the fluorocarbon chain, which is suitable for strong corrosion, strong oxidation, high vacuum or extreme temperature environments. Its lubricating film is not easily destroyed by chemicals and is suitable for semiconductor manufacturing, nuclear industry, aerospace and other fields.

7. Cost and maintenance requirements
Phenyl silicone oil:
The preparation process is mature and the cost is relatively low, but the lubricant needs to be regularly replenished or replaced at high temperatures, and the maintenance frequency is high.
Perfluoropolyether:
It has strong chemical stability and a long lubrication cycle, but the raw material cost is high and the preparation process is complex, resulting in expensive products. However, its long life and low maintenance requirements can reduce long-term use costs.

8. Environmental and safety performance
Phenyl silicone oil:
A small amount of volatile substances may be produced at high temperatures, and ventilation and environmental protection requirements must be paid attention to.
Perfluoropolyether:
It is chemically inert, harmless to the environment, and non-flammable, suitable for scenarios with extremely high safety requirements (such as aerospace, nuclear industry).

9. Application scenario selection
Phenyl silicone oil:
It is suitable for medium and high temperature industrial equipment (such as bearings, gears), electronic and electrical heat dissipation (good thermal conductivity is required) and metal die-casting release agent (using its volatility and lubricity).
Perfluoropolyether:
Applicable to extreme environments such as aerospace engine bearings, semiconductor manufacturing equipment, nuclear industry machinery, and scenarios that require long-term maintenance-free (such as lubricants for space machinery have been used for more than 40 years).