Phenylmethylsilicone fluid is a product in which some methyl groups in methylsilicone oil are replaced by phenyl groups, and the thermal expansion coefficient is small.

Introduction:
Colorless or pale yellow transparent oil. Flash point>300℃. The freezing point of 5mol% phenyl silicone oil is as low as -70℃, the surface tension is about 2.1×10-4～2.85×10-4N/cm, the relative density is 1.00-1.11, and the refractive index is 1.425～1.533. Good thermal stability, the gelation time in hot air at 250°C is 1750h, and it also has good radiation resistance and high oxidation stability, heat resistance, flame resistance, UV resistance and chemical resistance. It can be prepared by telomerization of the hydrolyzate of octamethylcyclotetrasiloxane, dimethyltetraphenyldisiloxane and methylphenyldiethoxysilane in the presence of a catalyst. Used as lubricating oil, heat exchange fluid, insulating oil, carrier of gas-liquid chromatography, etc. It is used for insulation, lubrication, damping, shockproof, dustproof and high temperature heat carrier, etc. It is an ideal liquid damping dielectric fluid for electronic instruments.

Methyl phenyl silicone oil has higher viscosity-temperature coefficient, lower freezing point and flash point than dimethyl silicone oil of the same viscosity, and its anti-compression performance changes faster in viscosity under pressure. Low phenyl silicone oil has remarkable low temperature resistance and fluidity at -70 ℃. With the increase of phenyl mole fraction, the high temperature resistance, radiation resistance, lubricity and solubility in organic solvents of silicone oil all improved; but the low temperature resistance decreased. Silicone oil with high phenyl molar fraction will oxidize when heated above 250 ℃, and its viscosity will increase; especially for silicone oil with 50% phenyl molar fraction, adding stabilizer can be used for hundreds of hours at 300-350 ℃.

Apply:
Due to its excellent performance, phenyl silicone oil can be applied to many fields of national life and production.
1. The use of methyl phenyl silicone oil in the application field of methyl silicone oil can give full play to its characteristics of low temperature resistance, high temperature resistance, lubricity and compatibility. Low phenyl silicone oil is especially suitable for occasions requiring high cold resistance; medium phenyl and high phenyl silicone oil has high thermal stability and good radiation resistance, and can be used as heat treatment bath for metal products, high temperature heating oil, gas chromatography Carrier, high and low temperature lubricating oil for electronic and electrical equipment, high temperature lubricating grease made of carbon black, lithium soap or molybdenum disulfide can be used for lubrication of high temperature fan bearings, ball bearings, automobile engines, textile dryers, etc.;
2. In addition, it is also widely used in hydraulic, instrumentation, electrical insulation and so on. Phenyl vinyl silicone oil and phenyl hydrogen silicone oil can be used to prepare high temperature and radiation resistant addition silicone rubber. Hydroxy-terminated phenyl silicone oil as a fabric finishing agent can significantly improve the smoothness and flexibility of the fabric, and endow the fabric with good hydrophobicity and oil repellency. Using the good compatibility of phenyl silicone oil as an internal additive of plastics can improve its processing performance.
3. Methyl phenyl silicone oil has better compatibility with cosmetic ingredients than methyl silicone oil, is stable to heat and ultraviolet rays, and has a unique luster. It is often used as an additive for personal care products such as skin care products and hair conditioners. Silicone oils containing methylphenylsiloxanes can be used to prepare colorless and transparent products with high phenyl content and moderate viscosity. Taking advantage of its high light transmittance, high refractive index, good thermal stability, and radiation resistance, it can be used For LED packaging materials.