Sodium carbonate perhydrate

In contrast with sodium perborate, which is a genuine peroxo compound. Sodium percarbonate is only a perhydrate. It has the composition Na2C03 I.5H2O2. It can be manufactured using dry and wet processes. In a modern dry process, hydrogen peroxide and a sodium carbonate solution are sprayed onto a fluidized bed of sodium percarbonate which is fluidized with warm air. The lines are returned to the process and the oversized particles are ground. 

In the wet process, sodium carbonate solution and hydrogen peroxide are reacted together in stoichiometric proportions. The percarbonate precipitates out upon cooling after vacuum concentration, if required. 

Stabilizers have to be added to sodium percarbonate, because it decomposes easily 

Since percarbonate is much less stable than perborate, stabilizers such as alkali silicates or phosphates are used in both processes. For its use in detergents it can also be coated with an organic or inorganic material to increase its stability. Its active oxygen content is ca. 13.5% (theoretically 15.28%). 

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The world capacity for sodium carbonate perhydrate is about 20% of that of sodium perborate, both products being alternately produced in some plants. About 40% of the hydrogen peroxide production of Western Europe is utilized in the production of sodium perborate and sodium carbonate perhydrate. 

Table 1.3-3. Sodium Carbonate Perhydrate consumption in 1991 (estimated) in 10 t.

Hydrogen Peroxide, Sodium Perborate and Sodium Carbonate Perhydrate... 

The oxidation of sulfides to sulfoxides (1 eq. of oxidant) and sulfones (2 eq. of oxidant) is possible in the absence of a catalyst by employing the perhydrate prepared from hexafluoroacetone or 2-hydroperoxy-l,l,l-trifluoropropan-2-ol as reported by Ganeshpure and Adam (Scheme 99 f°. The reaction is highly chemoselective and sulfoxidation occurs in the presence of double bonds and amine functions, which were not oxidized. With one equivalent of the a-hydroxyhydroperoxide, diphenyl sulfide was selectively transformed to the sulfoxide in quantitative yield and with two equivalents of oxidant the corresponding sulfone was quantitatively obtained. 2-Hydroperoxy-l,l,l-fluoropropan-2-ol as an electrophilic oxidant oxidizes thianthrene-5-oxide almost exclusively to the corresponding cw-disulfoxide, although low conversions were observed (15%) (Scheme 99). Deprotonation of this oxidant with sodium carbonate in methanol leads to a peroxo anion, which is a nucleophilic oxidant and oxidizes thianthrene-5-oxide preferentially to the sulfone. 

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