Study On The Control Of Properties Of High Viscosity Methyl-phenyl Silicone Oil

Phenyl-methyl silicone oil can be applied to many areas of national life and production because of its inoxidizability,lubrication,good organic intermiscibility,high refractive index,good thermal stability,resistance to high and low temperature(working temperature from-50 to 200℃)and resistance to radiation characteristics.High viscosity phenyl-methyl silicone oil with features and benefits in defense,life sciences,aerospace and other high-end with good prospects that can’t be replaced by low viscosity dimethyl silicone oil.For the moment,there are no such batch manufacturing enterprises producing high-end application products like this kind and most of the products are made by blending different viscosity phenyl-methyl silicone oil,and has the problem of small output,lack of specification,unstable quality and bad control of viscosity,which is not satisfying.Therefore,the preparation of high viscosity phenyl-methyl silicone oil has great value to be further researched and put into application.The preparation technology and principle of the high viscosity methyl-phenyl silicone oil including methyl-phenyl cyclotetarsiloxane system,octaphenylcyclotetrasiloxane system and condensation system were studied in this paper,finding that the key technology to produce the viscosity controllable high viscosity methyl-phenyl silicone oil are not the same.When using the methyl-phenyl cyclotetarsiloxane system and octaphenylcyclotetrasiloxane system,the main factors affecting the viscosity of the product are the moisture content in the raw materials,the amounts of blocking agent and when to add the blocking agent.Adding the blocking agent when the viscosity of the polymerization system increases rapidly keeps the viscosity under good control.When using the condensation system,the reaction time is the main factor affecting the viscosity of the product under other fixed conditions.At the beginning of the reaction,the viscosity of the product increases over condensation time.But after it reaches equilibrium,the viscosity of the product tends to be stable,since extending the reaction time has no obvious effect on the viscosity of the product.to meet customers’ requirements,that is,keeping the refractive index ≥1.4950,dynamic viscosity ≥1000mPa.s,and product transparency and viscosity controlled.The preparative technique of high viscosity and viscosity control were solved especially.Factors of influence of producing high viscosity phenyl-methyl silicone oil have been researched to determine and optimize the process.The preparation methods of different reparation systems have been researched and compared in the paper and the product of each method have been determined from the properties of viscosity,refractive index,transparency,heat resistance,etc.Meanwhile,based on the basic research on the process conditions,by-products treatment,raw material prices and main performance factors affecting the product,finally come to the conclusion that the octaphenylcyclotetrasiloxane system is currently the best route to produce high viscosity benzyl silicone oil.