Vapor-liquid equilibria for CF3OCF2H/fluorinated ethane and CF3SF5/fluorinated ethane mixtures as potential R22 alternatives

New vapor pressure data are reported as a function of temperature and conce ntration for the mixtures: CF3SF5/CF3CH3, CF3SF5/CF3CF2H, CF3OCF2H/CH3CH2F, CF3OCF2H/CH3CF2H, CF3OCF2H/CF3CH3, CF3OCF2H/CF3CH2F, andCF(3)OCF(2)H/CF3CF 2H. As is expected, large positive deviations from the ideal mixing vapor p ressure are observed for CF3SF5 mixed with ethane derivatives of a low fluo rine content and these deviations become small as the fluorine content appr oaches that of CF3CF2H. In contrast to this expected vapor pressure behavio r, the ether (CF3OCF2H)/fluorinated ethane mixtures exhibit significantly s maller deviations which may be positive or negative. The mixture, CF3OCF2H/ CH3CH2F, exhibits sufficiently large negative deviations from ideality to p roduce an azeotrope at 0.21 mol fraction of CH3CH2F with boiling point of - 33.3 degreesC. The mixtures CF3OF2H/CH3CF2H, CF3OCF2H/CF3CH3 and CF3OCF2H/C F3CF2H are nearly ideal and the mixture CF3OCF2H/CF3CH2F exhibits positive deviations from ideality. All of the mixtures have boiling points that rang e from -22 to -48 degreesC. The mixtures that have boiling points below -30 degreesC have potential as R22 alternatives. (C) 2001 Elsevier Science B.V . All rights reserved.