In addition, it is a non-flammable stable
azeotrope needing no testing for acid acceptance or stabilising additives, easy to use and maintain and safer for employees and the workplace.
[11.] Quantitative structure-property relationship (QSPR) modeling of normal boiling point temperature and composition of binary
azeotropes / V.P.
Two binary systems containing nonane exhibit minimum boiling
azeotropes. Azeotropic conditions have to obey to the following relationships:
The paper described halogen-free
azeotropes composed of various aliphatic hydrocarbons, carboxylic-acid esters, ketones, and ethers.
Several
azeotropes (refrigerant blends), such as "AZ20" tested by AlliedSignal, however, were shown to perform surprisingly well in drop-in tests.
In spite of a few exceptions and of a significant uncertainty band, [T.sub.c], therefore, proves to be a useful tool for a first order screening approximation to get an order of magnitude of the COP and volumetric capacity of various fluids, at least for pure fluids and
azeotropes. In the following sections, we will use the same classification also for zeotropic blends, although a more precise analysis of performance by applications will be needed, which will be the subject of part two of this article.
Criteria for the occurrence of
azeotropes in such systems have been presented in terms of liquid-phase activity coefficients at infinite dilution ([[gamma].sup.[infinity]]) for the isothermal case (Brandani, 1974), and for both isothermal and isobaric cases (Missen, 2005), including determination from [g.sup.E] expressions.
HFEs do not have hydrocarbon solvency to match the ODS solvents, but since they can be mixed with other solvents to form
azeotropes or co-solvent systems, they can be just as effective in cleaning.
Pure refrigerants and
azeotropes have a single saturation temperature at a given pressure.