A retarder is a chemical agent that slows down a

chemical reaction A chemical reaction is a process that leads to the chemistry, chemical transformation of one set of chemical substances to another. When chemical reactions occur, the atoms are rearranged and the reaction is accompanied by an Gibbs free energy, ...

. For example, retarders are used to slow the chemical reaction hardening of plastic materials such as wallboard,

concrete Concrete is a composite material composed of aggregate bound together with a fluid cement that cures to a solid over time. It is the second-most-used substance (after water), the most–widely used building material, and the most-manufactur ...

, and

adhesive Adhesive, also known as glue, cement, mucilage, or paste, is any non-metallic substance applied to one or both surfaces of two separate items that binds them together and resists their separation. The use of adhesives offers certain advantage ...

s. Sugar water acts as a retarder for the curing of concrete. It can be used to retard the chemical hardening of the surface, so that the top layer can be washed off to expose the underlying aggregate.

References

Chemical reactions {{reaction-stub

See also

References