Dimethyl sulfone is a very stable compound. When heated in the presence of air at 140°C for 96
hours, purity as measured by gas chromatography (GC) revealed that less than 0.2 wt% of the sam-
ple had decomposed in this time. Heating dimethyl sulfone to 275 °C for one hour resulted in a de-
composition of 0.03 mole percent. It did not decompose when heated to 238 °C for two hours in the
presence of water and sodium hydroxide in an autoclave. Neither did it decompose when heated to
130 °C for three hours with a nitrating mixture of fuming sulfuric and fuming nitric acids. The proven
stability of dmethyl sulfone at reflux temperature may well be its most valuable physical property.
This suggests that dimethyl sulfone may be useful as a high temperature heat transfer fluid.
Regarding sublimation, Thermogravimetric Analysis (TGA) measurements suggest that DMSO2 sub-
limes at the rate of 74 wt% / hour, at 80°C. At 160°C, all of the sample sublimed within a few min-
utes.
DCS analysis detects the two phase changes of DMSO2, and suggests that vapor pressure of the
molten sample is significant between the melting and boiling points of DMSO2.