Malonic acid dihydrazide is primarily used in the synthesis of polymers and resins, where it acts as a cross-linking agent to enhance the mechanical and thermal properties of the materials. It is also employed in the production of foams and adhesives, providing improved stability and durability. In the pharmaceutical industry, it serves as an intermediate in the synthesis of various active compounds, particularly those with hydrazide functional groups. Additionally, it finds application in the field of organic synthesis, where it is utilized to create heterocyclic compounds, which are important in the development of dyes, agrochemicals, and other specialty chemicals. Its ability to form stable complexes with metal ions makes it useful in certain analytical and industrial processes.