What is DMAC? A Detailed Introduction

Freezing point -20°C, boiling point 166°C, 96°C (10.7kPa), 85-87°C (4.4kPa), 74-74.5°C (3.47kPa), 66-67°C (2.0kPa), 62-63°C (1.6kPa); relative density 0.9366 (25/4°C), 0.9599 (0/4°C); refractive index 1.4380. Flash point (open cup) 70°C. Low toxicity, strong pungent odor.

Dimethylacetamide(DMAC) can dissolve a variety of compounds and is completely miscible with water, ethers, ketones, esters, etc. It features high thermal stability, resistance to hydrolysis, low corrosivity, and has a wide range of applications. Dimethylacetamide has good solubility for many resins, especially polyurethane resins and polyimide resins, and is mainly used as a solvent for heat-resistant synthetic fibers, plastic films, coatings, pharmaceuticals, and acrylonitrile spinning. Overseas, it is mostly used in the production of polyimide films, soluble polyimides, polyimide-perfluoropropylene composite films, polyimide (aluminum) films, soluble polyimide molding powders, etc.; domestically, it is mainly used as an excellent polar solvent for polymer synthetic fiber spinning and other organic syntheses.

In organic synthesis, dimethylacetamide is an excellent catalyst that can accelerate reactions such as cyclization, halogenation, cyanation, alkylation, and dehydrogenation, and can improve the yield of main products. In the production of some pharmaceuticals and pesticides, dimethylacetamide can also be used as a solvent or co-catalyst, which improves product quality and yield compared with traditional organic solvents.

The industrial production routes of dimethylacetamide are mainly divided into acetic anhydride method, acetyl chloride method, and acetic acid method according to raw materials. The acetic anhydride method uses acetic anhydride as raw material and reacts with dimethylamine in the gas phase to obtain the product, which is currently the main production method in China; the acetyl chloride method obtains the product by reacting dimethylamine with acetyl chloride, and this process is characterized by adopting advanced catalytic reactive distillation technology, which can enhance the reaction, reduce energy consumption, greatly improve separation efficiency and product yield, simplify the process, and reduce production costs compared with the acetic anhydride method; the acetic acid method involves the condensation reaction of acetic acid and dimethylamine in the presence of a catalyst to obtain the product. Domestically, catalytic distillation technology has been successfully adopted for direct synthesis, utilizing reaction heat, reducing energy consumption during the reaction, and greatly shortening the process flow since the reaction and distillation are completed in the same equipment. In addition, it is worth noting that overseas industrial production of dimethylformamide mostly adopts the advanced one-step synthesis method of carbon monoxide/dimethylamine, and some dimethylacetamide is often obtained in this process route.