MEASUREMENT OF THE SURFACE TENSION OF SANTOWAX 'R', PARA-, META-, AND ORTHO- TERPHENYL, DIPHENYL, DIPHENYL ETHER AND DOWTHERM 'A'

Values of surface tension were obtained over the temperature range from near the melting point to near the normal boiling point of each substance. A capillary rise method was used employing a closed glass U-tube apparatus. The accuracy was plus or minus 3% near the melting point falling to plus or minus 5% near the normal boiling point. Values of the parachor calculated from the experimental data were in excellent agreement with those calculated from the molecular structure using the method proposed by Sugden. The surface tension in each case decreased with ascending temperature from near 30 to 40 dynes/cm close to the melting point to 13 to 15 dynes/cm near the normal boiling point. (auth)