Why CFCs as Propellants?

What are the advantages to using a CFC as a propellant from an aerosal can? I WAG it is easily stored as a liquid and can rapidly vaporize (or flash) to a vapor?

  • Jinx :confused:

What you posted is true, also at the time they were introduced, they were thought to be harmless to the enviroment.

CFCs won’t burn, so there less fire hazard. They also don’t react chemically with the hairspray/medicine/paint/bugkiller you’re trying to move.

Neither would Neon /Argon/ etc. Are/were CFCs that much cheaper than noble gases?

None of the noble gasses is liquid at reasonable temperature and pressure for putting in an aerosol can. If you can use a liquid-gas phase changing propellant, it makes your package much smaller and lighter.

Another reason CFCs were used is that it can be advantagous if the product is misable in the propellant. Liquid R-12 is/was a pretty fair solvent (closely relate to 1-1-1 trichloroethane which was used for dry cleaning) so a lot of products were misable in it.

And they smell much better than ammonia, which would boil nicely and be nonflammable. By “ammonia” I mean pure NH3, not the weak solution of it they sell in stores (which is like mother’s milk in comparison).

Right…I was wondering why N2 wasn’t a gas of choice being inert as the noble gases and more abundant. But, it would not be practical in an aerosal can. :frowning:

  • Jinx

Plus, by tinkering with the exact molecular formula (how big a carbon chain, ratio/chain position of chlorine & fluorine), it’s easy to tailor the CFC to get the optimum boiling point for the application you want.