Lubricants, CFCs

Refrigerant Lubricant (H)CFC Service blends HFC + blends Hydro- carbons Ammonia... 

The propellants used were some years agochloro-fluorocarbons (CFCs) (11 and 12) in various proportions (65 35 or 50 50). The manufacturing process includes the suspension formation in liquid propellant 11 in a cooled and hermetically closed mixer containing drug and lubricants. This mixture is introduced in the cans that are closed by a special powder valve, and propellant 12 was then injected through the valve. The upper part of the valve has often a special aperture through which a gaseous phase cleans the valve as well as the actuator. 

With chlorofluorocarbons, CFCs, now phased out of use due to their ozone-depleting effects, traditional naphthenic and paraffinic mineral oils used in refrigeration lubricants are being replaced by polyol ester oils. The main reason for the replacement is that traditional mineral oils are immiscible with the more polar hydrofluorocarbons, HFCs, which have replaced CFCs [58]. 

Randles, S.I., Taylor, P.I., Corr, S., Dekleva, T. and Stewart, A. (1994) Development and Experience with Polyol Ester Lubricants for Use with RI34a Domestic Refrigerators. CFC Halocarbon Conference. 

Because CFCs are being relegated to history, this chapter will concentrate on the new HFAs. Three main factors control formulation approaches, and only one of these is pharmaceutical in nature. HFA 227 and HFA 134a are very poor solvents, hence the existing CFC sur-factants/valve lubricants are not soluble in the HFAs. The second factor which is related is that any new surfactant must have adequate drug safety data, and this could mean a full New... 

The CFC substitutes for the refrigeration sector require new lubricants for operation of the compressors. Ester of w-valeric acid are used for this purpose. The starting product for this acid is n-valeraldehyde. The production plant concept involves manufacture of n-valeraldehyde and amyl alcohol. 

Apart from lactose as carrier or filler, DPls do not have to incorporate the lubricants and cosolvents needed in propellant driven pMDIs. These additives may be the cause of commonly observed cough (93) and bronchoconsttiction when a patient is inhaling from a pMDI (50), though the latter is often masked by the drug effect. As mentioned earlier, the CFC propellant of the pMDI has been withdrawn due to the detrimental effect of CFCs on the ozone layer. CFCs have now been replaced by HFA propellants, which should have no effect on the ozone layer. They are, however, considered as greenhouse gases. In fact, they are several thousand times more potent than carbon dioxide. 

Uses Vapor degreasing applies. cleaning/rinsing agent drying fluid fluorocarbon lubricant carrier solvent and disp. media heat transfer media CFC replacement... 

Collection of samples for organic component analysis has a number of special difficulties. The sampling platform (i.e., the ship) is a considerable source of organic material, notably hydrocarbons from fuel and lubricating oil residues and CFCs/halons from refrigeration and fire-fighting equipment. Considerable attention must therefore be paid to sample design such that the sampler can be deployed, retrieved, and the sample processed without exposure to external contaminants. 

Uses Detergent, dispersant, particle suspending agent, antistat, wetting agent, o/w emulsifier, conditioner, penetrant, lubricant for cosmetics, toiletries, conditioning shampoos, textiles, industrial slurries, dry cleaning Properties Lt. amber cl. liq. sol. in water, IPA, perc, Stod., kerosene, CFC, oil sp.gr. 1.01 flash pt. > 93 C pH 6.5 (10% aq.) 98% cone. 

Uses Detergent o/w emulsifier lubricant alkalinity builder neutralizer conditioner dispersant for aq. and nonaq. systems charge soap in dry cleaning Properties Sol. in water, oil, alcohol, perc, Stod., kerosene, CFC Witcamide 61 [Witco ]... 

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