Sodium nonanoyloxybenzenesulfonate (NOBS) is an important component of

laundry detergent Laundry detergent is a type of detergent (cleaning agent) used for cleaning dirty laundry (clothes). Laundry detergent is manufactured in powder (washing powder) and liquid form. While powdered and liquid detergents hold roughly equal share o ...

s and bleaches. It is known as a bleach activator for

active oxygen Oxygen is the chemical element with the symbol O and atomic number 8. It is a member of the chalcogen group in the periodic table, a highly reactive nonmetal, and an oxidizing agent that readily forms oxides with most elements as well a ...

sources, allowing formulas containing

hydrogen peroxide Hydrogen peroxide is a chemical compound with the formula . In its pure form, it is a very pale blue liquid that is slightly more viscous than water. It is used as an oxidizer, bleaching agent, and antiseptic, usually as a dilute solution (3%� ...

releasing chemicals (specifically

sodium perborate Sodium perborate is chemical compound whose chemical formula may be written , , or, more properly, ·. Its name is sometimes abbreviated as PBS (not to be confused with phosphate-buffered saline). The compound is commonly encountered in anhydr ...

sodium percarbonate Sodium percarbonate is a chemical substance with formula . It is an adduct of sodium carbonate ("soda ash" or "washing soda") and hydrogen peroxide (that is, a perhydrate) whose formula is more properly written as 2 · 3 . ...

sodium perphosphate Sodium is a chemical element with the Symbol (chemistry), symbol Na (from Latin ''natrium'') and atomic number 11. It is a soft, silvery-white, highly reactive metal. Sodium is an alkali metal, being in group 1 element, group 1 of the ...

sodium persulfate Sodium persulfate is the inorganic compound with the formula Sodium, Na2Sulfur, S2Oxygen, O8. It is the sodium salt of peroxydisulfuric acid, H2S2O8, an oxidizing agent. It is a white solid that dissolves in water. It is almost non-hygroscopic an ...

, and urea peroxide) to effect bleaching at lower temperatures.

Synthesis

NOBS is formed by the reaction of nonanoic acid (or its

ester In chemistry, an ester is a compound derived from an oxoacid (organic or inorganic) in which at least one hydroxyl group () is replaced by an alkoxy group (), as in the substitution reaction of a carboxylic acid and an alcohol. Glycerides a ...

s) with

phenol Phenol (also called carbolic acid) is an aromatic organic compound with the molecular formula . It is a white crystalline solid that is volatile. The molecule consists of a phenyl group () bonded to a hydroxy group (). Mildly acidic, it ...

followed by

aromatic sulfonation Aromatic sulfonation is an organic reaction in which a hydrogen atom on an arene is replaced by a sulfonic acid functional group in an electrophilic aromatic substitution. Aryl sulfonic acids are used as detergents, dye, and drugs. Stoichiomet ...

using SO₃ to form a sulfonic acid at the para-position.

Bleach activation

NOBS was developed by

Procter & Gamble The Procter & Gamble Company (P&G) is an American multinational consumer goods corporation headquartered in Cincinnati, Ohio, founded in 1837 by William Procter and James Gamble. It specializes in a wide range of personal health/consumer he ...

in 1983 and was first used in American laundry detergents in 1988. NOBS is the main bleach activator used in the U.S.A. and Japan. Compared to TAED, which is the predominant bleach activator used in Europe, NOBS is efficient at much lower temperatures. At 20 °C NOBS is 100 times more soluble than TAED in water. When attacked by the perhydroxyl anion (from hydrogen peroxide), NOBS forms the peroxy acid peroxynonanoic acid and releases the leaving group sodium 4-hydroxybenzene sulfonate, which is an inert by-product.

References

{{reflist Cleaning product components Benzenesulfonates Anionic surfactants Organic sodium salts Nonanoate esters