A chemical reaction in which a substance reacts with water and becomes a different substance. This involves the ionization of the water molecule, as well as splitting of the compound hydrolyzed. An example is the chemical reaction of salt with water, which then forms an acid and a base. The chemical process in which scission of a chemical bond occurs via reaction with water. The reaction of a salt with water to form an acid and a base.

The polyester chemical bonds in tape binder polymers are subject to hydrolysis, producing alcohol and acid end groups. Hydrolysis is a reversible reaction, meaning that the alcohol and acid groups can react with each other to produce a polyester bond and water as a by-product. In practice, however, a severely degraded tape binder layer will never fully reconstruct back to its original integrity when placed in a very low-humidity environment.