1,1,3,5,5-PENTAPHENYL-1,3,5-TRIMETHYLTRISILOXANE
Chemical Structure
Introduction
SiSiB® PF8705 Silicone Diffusion Pump Fluid is a single component fluid designed for ultrahigh vacuum applications in the range of 10-9 to 10-10 torr (untrapped) and 10-11 torr (trapped). The low vapor pressure, low back-streaming rate and the high resistance to oxidation and radiation make this diffusion pump fluid ideal for many ultrahigh vacuum applications such as those in mass spectrometers and electron microscopes.
It has the highest phenyl content of all silicone diffusion pump fluids and the best resistance to radiation. High spontaneous ignition temperature makes this fluid ideal for use in human-rated space simulation chambers.
SiSiB® PF8705 is equal to DowCorning’s DC-705, Shin-Etsu’s HIVACF-5.
Typical Physical Properties
| Product: | SiSiB®PF8705 |
|---|---|
| CAS No.: | 3982-82-9 |
| EINECS No. | 222-222-9 |
| Formula | C33H34O2Si3 |
| Molecular Weight: | 546.88 |
| Color and Appearance: | Colorless to straw-colored fluid |
| Ultimate Vacuum, torr | 10-9 to 10-10 untrapped |
| 10-11 trapped | |
| Extrapolated Vapor Pressure, | 3 x 10-10 torr, 25°C |
| Specific Gravity at 25°C | 1.09 |
| Viscosity at 25°C | 175cSt |
| Flash Point, open cup | 243°C |
| Boiling Point, 0.5 torr | 245°C |
| Typical Boiler Temperature | 250-270°C |
| Surface Tension, dynes/cm | 36.5 |
| Heat of Vaporization, kcal/g mol | 28.5/250°C |
Applications
SiSiB® PF8705 Diffusion Pump Fluid can be used in a variety of applications including: Aerospace, Electronics, Metallurgy, Vacuum Coatings, and Atomic Energy etc.
Packings
SiSiB® PF8705 is supplied in 5Kg, 25Kg pail or 200Kg steel drum, for more details, please visit Packing Centre.