Dimethylacetamide (DMAC), with the chemical formula C₄H₉NO, is a clear, colorless, hygroscopic liquid with a faint ammonia-like odor. It is a highly polar, high-boiling organic solvent used widely in the pharmaceutical, textile, polymer, and chemical synthesis industries. Known for its strong solvency power, DMAC is especially effective in dissolving resins and polymers such as polyacrylonitrile, polyimides, and polyurethane. It is also commonly used in fiber spinning, film coatings, and reaction media for organic synthesis.