Experimental Investigation on the Surface Tension of R1234ze(E)/POE Lubricant Mixtures from 278 K to 338 K

The surface tension of the mixtures of R1234ze(E) with two POE lubricant oils (RL68H and SL32S) was measured at temperatures from 278 K to 338 K. The experimental system which is established based on differential capillary rise method was used for the present measurement. The surface tension enhancement rate of R1234ze(E)/RL68H and R1234ze(E)/SL32S mixtures compared to pure R1234ze(E) was discussed. In addition, the surface tension data were correlated as a function of temperature and lubricant oil mass fraction. The average absolute deviation for R1234ze(E)/RL68H and R1234ze(E)/SL32S mixtures between experimental data and calculated values was 0.08 mN·m⁻¹ and 0.06 mN·m⁻¹, respectively.