LITMIR.BIZ

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0 Zero 3143 422D 0 Zero 2729 423A 0 Zero 2280 424A 0 Zero 2440 427A 0 Zero 2138 428A 0 Zero 3607 434A 0 Zero 3245 437A 0 Zero 1805 438A 0 Zero 2265 442A 0 Zero 1888 507A 0 Zero 3985 508B 0 Zero 13396

      Priority order of atoms connected to either of the unsaturated carbons is determined by standard CIP (Cahn-Ingold-Prelog) rules of organic nomenclature [11]. In essence, attached atoms of higher atomic number have higher priority: I>Br>Cl>F>O>C>H. In case of a priority tie, the next attached atoms or substituents on the next attached carbon atom are considered, until a priority is determined. In the case of refrigerants, it is more exact and less cumbersome to use atomic mass rather than atomic numbers of the atoms. This is because the sum of the atomic numbers of substituents of CHF₂ and CHCl are the same, while the summed atomic masses do differ.

In case of Composition-Designating Prefixes the identifying Number is prefixed by the letter C, for carbon, and preceded by B, C, or F—or their combinations—to signify the presence of bromine, chlorine, or fluorine, respectively. In compounds that also contain hydrogen the codes are preceded by the letter H, to signify the increased deterioration potential before reaching the stratosphere. The compositional designating prefixes for ether substitute an “E” for “C,” such that “HFE,” “HCFE,” and “CFE” refer to hydrofluoroethers, hydrochlorofluoroethers, and chlorofluoroethers, respectively. The composition designating prefixes for halogenated olefins is “CFC”, “HCFC”, or “HFC” referring to chlorofluorocarbon, hydrochlorofluorocarbon, or hydrofluorocarbon, respectively. With substitution of an “O” for the carbon “C” as “CFO”, “HCFO” and “HFO” refer to chlorofluoro-olefin, hydrochlorofluoro-olefin, or hydrofluoro-olefin, respectively.

      Table 2.5 Main applications for HFC and PFC substitutes¹ for Ozone Depleting Fluorocarbons (ODS) [9].

Chemical	Refrigeration and air conditioning	Fire suppression and explosion protection	Aerosols		Solvent cleaning	Foam blowing	Other Application2
			Propellants	Solvents
HFC-23	X	X
HFC-32	X
HFC-125	X	X
HFC-134a	X	X	X			X	X
HFC-143a	X
HFC-152a	X		X			X
HFC-227ea	X	X	X			X	X
HFC-236fa	X	X
HFC-245fa				X		X
HFC-365mfe				X	X	X
HFC-43-10mee				X	X
PFC-143 (CF4)		X
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