- Not to be confused with potassium peroxymonosulfate.
Potassium persulfate is the inorganic compound with the formula K2S2O8. Also known as potassium peroxydisulfate or KPS, it is a white solid that is highly soluble in water. This salt is a powerful oxidant, commonly used to initiate polymerizations.
- 2 KHSO4 → K2S2O8 + H2
It can also be prepared by adding potassium bisulfate (KHSO4) to a solution of the more soluble salt ammonium peroxydisulfate (NH4HSO4). In principle it can be prepared by chemical oxidation of potassium sulfate using fluorine.
This salt is used to initiate polymerziation of various alkenes leading to commercially important polymers such as styrene-butadiene rubber and polytetrafluoroethylene and related materials. In solution, the dianion dissociates to give radicals:
As a strong bleaching agent, it is used in hair dye substances as whitening agent with hydrogen peroxide.
The salt is a strong oxidant and is incompatible with organic compounds.
- F. Feher, "Potassium Peroxydisulfate" in Handbook of Preparative Inorganic Chemistry, 2nd Ed. Edited by G. Brauer, Academic Press, 1963, NY. Vol. 1. p. 392.
- Encyclopedia of Reagents for Organic Synthesis, vol. 1, pp 193-197(1995)