| 摘要 |
Systems contain siloxanes of formula RSi OSi(OR1)3 3, (in which R and R1 are H, alkyl, alkenyl, aryl or aralkyl, most of the R1 gps. being steric-hindered >=3C alkyl gps. Used as hydraulic braking, control, transfer, elevating and conveyor systems in road vehicles, building, railways, mining, water vehicles, aircraft, etc. Also in heat circulation and exchange systems in chemical plant, coolants for nuclear reactors, etc. They have good hydrolytic stability and lubricating properties, and low viscosities, which allow their use with or without other additives. A fluid of formula CH3Si OSi(sec.C4H9O)3 3 shows a viscosity-temp. curve by ASTM D341-43 of 0.45 without additives. Lubricating properties and hydrolysis resistance are also good without additives and flash point is 198.9 degrees C. |
