N,N-Dimethylacetamide (DMAC) is an important organic chemical raw material, which is widely used in pharmaceuticals, pesticides, synthetic fibers, plastics, rubber and other fields. In this paper, we will introduce the manufacturing method of DMAC, including the steps of raw material preparation, reaction process, and post-treatment.
I. Raw material preparation
The main raw materials for manufacturing DMAC are dimethylamine and acetic anhydride. Dimethylamine is a colorless and transparent liquid with strong ammonia odor, easily soluble in water, ethanol and ether. Acetic anhydride is a colorless transparent liquid with irritating odor, soluble in water, ethanol and ether.
II. Reaction process
1. add dimethylamine and acetic anhydride into the reactor according to a certain molar ratio, generally the molar ratio of dimethylamine and acetic anhydride is 1:1.1-1.2.
2. turn on the stirring at a certain temperature, so that the dimethylamine and acetic anhydride are fully mixed.
3. A large amount of heat is generated during the reaction process, and it is necessary to control the reaction temperature by cooling water or frozen brine to keep the reaction temperature within a certain range.
4. At the end of the reaction, leave the reaction solution for a period of time to separate the DMAC from the aqueous layer.
3. Post-treatment
1. Distill the separated DMAC crude product to obtain DMAC product with higher purity.
2. The distillation residue is treated, which can recover unreacted raw materials and by-products.
4. Precautions
1. In the manufacturing process, pay attention to control the reaction temperature and pressure to avoid overheating and overpressure.
2. A large amount of irritating gas will be generated during the reaction process, good ventilation and protective measures are required.
3. In the post-treatment process, attention should be paid to operational safety to avoid burns and contact with irritating substances.
All in all, manufacturing DMAC requires certain chemical knowledge and skills, as well as attention to safety and environmental protection requirements. Only by constantly summarizing experience in actual operation can we improve manufacturing efficiency and product purity and create greater economic and social benefits for the enterprise.
