Deamidization is a process that involves removing or reducing the amount of amide groups from a molecule. The purpose of this process is to improve the material's ability to resist water, oxidation and increase its durability. It is also used to prepare materials that are resistant to acid or alkali. Deamidization is commonly used in the production of textile, paper, medical, food and electronics products.

During deamidization, a reactive agent such as phosphorus pentoxide (P2O5), hydrogen chloride (HCl) or sulfuric acid (H2SO4) is used.