Properties of Sulfolane Quoted in the Literature
Other properties
|
Vapour pressure |
@ 150℃ |
14.53 mmHg |
|
|
@ 200℃ |
85.23 mmHg |
|
|
@ 250℃ |
333.7 mmHg |
|
Critical temperature |
528℃ (801 K) |
|
|
Critical pressure |
52.2 Atmospheres |
|
|
Dipole moment (benzene) |
4.69 Debyes |
|
|
Dielectric constant (30℃) |
44 |
|
Sulfolane has exceptional chemical and thermal stability. It only decomposes at temperatures above 220°C, and then only to give off sulphur dioxide. Sulfolane, therefore, has to be distilled under reduced pressure. The following dissociation rates have been observed for Sulfolane in glass with inert gas or air bubbling (decomposition was measured by the generation of sulphur dioxide).
|
Bubbled Gas |
Temperature (℃) |
Rate of Decomposition |
|
Nitrogen |
200 |
0.002 |
|
Nitrogen |
220 |
0.010 |
|
Nitrogen |
23 |
0.02 |
|
Carbon Dioxide |
200 |
0.002 |
|
Air |
200 |
0.009 |
Melting point determinations on Sulfolane samples after prolonged exposures (150- 500 hours) under the above conditions showed that very little reduction in purity occurred, although considerable discolouration was observed. Tests on Sulfolane (with and without small amounts of water and hydrocarbon) and carbon steel at 200°C showed that negligible corrosion occurred.