Heptafluoropropane HFC

HFA227 HFC227 Dymel 227 EA/P 2-hydroperfluoropro-pane P-227 propellant 227 R-227 Solkane 227 Zephex 227 EA. 

Heptafluoropropane is a liquefied gas and exists as a liquid at room temperature when contained under its own vapor pressure, or as a gas when exposed to room temperature and atmospheric pressure. The liquid is practically odorless and colorless. The gas in high concentration has a faint etherlike odor. Heptafluoropropane is noncorrosive, nonirritating, and nonflammable. 

Heptafluoropropane (P-227) is classified as a hydrofluorocarbon (HFC) aerosol propellant since the molecule consists only of carbon, fluorine, and hydrogen atoms. It does not contain any chlorine and consequently does not affect the ozone layer, nor does it have an effect upon global warming. It is therefore considered as an alternative propellant to CFCs for metered-dose inhalers (MDIs). While some of its physical and chemical properties are known, little has been published in regard to its use as a replacement for CFCs in MDIs. 

The vapor pressure of heptafluoropropane (P-227) is somewhat lower than that of tetrafluoroethane and dichlorodi-fluoromethane but considerably higher than the vapor pressure used to formulate most MDIs. 

When heptafluoropropane (P-227) is used for pharmaceutical aerosols and MDIs, the pharmaceutical grade must be specified. Industrial grades may not be suitable due to their impurity profile. 

---

Entrants were provided with the experimental bubble points for 15 mixture compositions of 1,1,1,2,3,3,3-heptafluoropropane (HFC-227ea) and ethanol at 283.17 K, and properties of the pure materials at 343.13 K. The challenge was to compute bubble points for seven mixture compositions at 343.13 K, using any experimental data for the pure components but the only mixture points at 283.17 K. Entries using any theory/modeling/simulation method were accepted. Entries were judged based on the criterion. 

The halocarbon gases such as pentafluoroethane (HFC-125), 1,1,1,3,3,3-hexafluoropropane (HFC-236fa) and 2H-heptafluoropropane (HFC-227ea) are manufactured by either vapor phase or liquid phase catalytic fluorination pathways in continuous mode of operation. The successful catalysts for vapor phase fluorination processes are usually chromium (111) oxide (preactivated with HF) and/or aluminum compoimds doped with Lewis acids such as Co, Ni or Zn. Similarly, antimony (V) chlorofluoride (SbCl Fp/HF is preferred as catalyst in liquid phase fluorination of chlorinated starting compounds. Some of the methods practiced for obtaining individual halocarbons are listed here. 

---