HFC－125表面张力的试验研究

Experimental research on surface tension of HFC-125

为了适应国际上《蒙特利尔议定书》即将禁用ＣＦＣ与ＨＣＦＣ类物质的紧迫要求，寻求它们的替代物成了当务之急。ＨＦＣ－１２５是迄今为止所有用以替代ＨＣＦＣ－２２的混合工质中必不可少的一种组份，而其物性研究还十分欠缺，特别是它的表面张力研究尤为少见。因此本文发表了在２３３．１５～３３３．１５Ｋ温度范围内，通过精密测量获得的２１组ＨＦＣ－１２５表面张力实验数据。实验所用的样品纯度为９９．９８％。这些数据是利用毛细管表面张力实验装置，分别按两种方法─—绝对法和相对法测量计算得到的。不同方法的结果吻合得很好，相对偏差在０．２％以内，绝对偏差小于０．０１ｍＮ／ｍ，所测得的数据具有很高的可信性。最后还通过对实验数据拟合，提出了该温度范围内ＨＦＣ－１２５表面张力与温度间的关联式。

To meet the restriction of the Montreal protocol,a hydrofluorocarbon(HFC)whose ozone depletion potential(ODP)value is zero to replace chlorofluorocarbon(CFC)and hydrochlorofluorocarbon(HCFC)should be looked for. The binary and/or ternary mixtures using HFC-125 as a component are thought to be the most promising alternatives for HCFC-22. Unfortunately,reliable thermophysical property data for HFC-125 are limited. In particular, there are few publishied surface tension data for HFC-125. A set of accurate surface tension data for HFC-125 has been measured using both an absolute capillary rise technique and a differential capillary rise technique at 233.15-333. 15K. The purity of the HFC-125 sample provided by I.C.I was 99. 98%. The two sets of experimental results using the absolute capillary rise method are consistent with each other,and agree well with the experimental results using the differential capillary rise method.The absolute deviations between these two methods are equal to or less than 0.01 mN.m-1.The relative deviations are equal to or less than 0. 2%.A van der Waals surface tension correlation has also been proposed.