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 of ...

s and

bleach Bleach is the generic name for any chemical product that is used industrially or domestically to remove color from (i.e. to whiten) fabric or fiber (in a process called bleaching) or to disinfect after cleaning. It often refers specifically t ...

es. It is known as a

bleach activator Bleach activators are compounds that allow a lower washing temperature than would be required otherwise to achieve the full activity of bleaching agents in the wash liquor. Bleaching agents, usually peroxides, are usually sufficiently active only ...

for active oxygen 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 viscosity, viscous than Properties of water, water. It is used as an oxidizer, bleaching agent, and antiseptic, usua ...

releasing chemicals (specifically

sodium perborate Sodium perborate are chemical compounds with chemical formula (H2O)x. Commonly encountered salts are the anhydrous form (x = 0) and as a hydrate, hexahydrate (x = 6). These two species are sometimes called, respectively, "monohydrate" or PBS-1 a ...

sodium percarbonate Sodium percarbonate or sodium carbonate peroxide is an inorganic compound with the formula . It is an adduct of sodium carbonate ("soda ash" or "washing soda") and hydrogen peroxide (that is, a perhydrate). It is a colorless, crystalline, hygros ...

, sodium perphosphate,

sodium persulfate Sodium persulfate is the inorganic compound with the formula Na2 S2 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 and has good shelf-life. ...

, 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 acid (either organic or inorganic) in which the hydrogen atom (H) of at least one acidic hydroxyl group () of that acid is replaced by an organyl group (R). These compounds contain a distin ...

s) with

phenol Phenol (also known as carbolic acid, phenolic acid, or benzenol) is an aromatic organic compound with the molecular formula . It is a white crystalline solid that is volatile and can catch fire. The molecule consists of a phenyl group () ...

followed by aromatic sulfonation using SO₃ to form a

sulfonic acid In organic chemistry, sulfonic acid (or sulphonic acid) refers to a member of the class of organosulfur compounds with the general formula , where R is an organic alkyl or aryl group and the group a sulfonyl hydroxide. As a substituent, it is kn ...

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. It was founded in 1837 by William Procter and James Gamble. It specializes in a wide range of personal health/con ...

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 peroxynonanoic acid (a peroxy 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