Polycarboxylate
The co-builder that keeps loosened soil in the water instead of letting it settle back onto the wash.
In detail
A polycarboxylate is a water-soluble polymer carrying many carboxylate groups along its chain. In a detergent it does two jobs at once. It binds hardness ions, supporting the main builder; and it adsorbs onto suspended soil particles and onto the fabric, giving both a negative charge so that they repel one another. That second job is the one worth understanding, because it addresses a failure most people have seen without diagnosing. A wash that removes soil and then lets it settle evenly back over everything produces a load that is uniformly dingy rather than spotted — nothing looks stained and nothing looks clean. Anti-redeposition chemistry exists to prevent exactly that, and polycarboxylates are the modern form of it. Declared on a label by class and weight band above 0.2%.
Why
- Polycarboxylate is explained by Residue and resoiling
- Polycarboxylate is explained by Builders and water softening
Sources for this page
Sources
Regulation (EC) No 648/2004 on detergents, Annex VII — labelling and ingredient data sheet
European Parliament and Council, as retained in UK law (legislation.gov.uk), 2004 · Government or regulator
Relied on for: That the class is one of the constituents a detergent label must declare, in weight bands above 0.2%. (states this directly)
Verification: a person has read the passage relied on.
Read on — Annex VII section A, the weight-range list and the declare-regardless list. Supports the claim as stated. Enumerates the ingredient-class family completely, and supplies the vocabulary a reader is actually confronted with on the back of a bottle.
Handbook of Detergents (Surfactant Science Series)
CRC Press / Taylor & Francis · Reference work
Relied on for: That polycarboxylates act as co-builders and anti-redeposition agents, binding hardness ions and dispersing soil so it does not redeposit on the wash. (background and mechanism only)
Verification: the work exists and is described correctly. Nobody has yet read the specific passage.
Last reviewed by a person on .