Uses of anhydrous acetonitrile_Kain Industrial Additives

Background and overview^[1]

Anhydrous acetonitrile is also called methylnitrile, cyanomethane, and Ethanenitrile. Colorless transparent liquid. Has an ether-like smell. Found in small amounts in coal tar. Produces a bright flame when burning. Relative molecular mass 41.05. Relative density 0.7857. Melting point -45.7℃. Boiling point 81.6℃. Flash point 12.8℃. Refractive index 1.3442. Viscosity 0.340mPa·s (25℃). Vapor pressure 9.729×103Pa (20℃). Freely miscible with water, methanol, ethanol, ether, acetone, benzene, methyl acetate, ethyl acetate, chloroform, vinyl chloride, carbon tetrachloride and certain unsaturated hydrocarbons. It forms an azeotropic mixture with water, with an azeotropic point of 76°C and containing 84% of this product. Under the action of strong acid and strong alkali, it is prone to hydrolysis, and acetic acid is generated after hydrolysis. Ethylamine is generated during reduction and can be polymerized into dimers or trimers. It has the chemical properties of nitriles. Reacts with hydrogen sulfide to form thioacetamide. .

Purpose^[2-3]

Anhydrous acetonitrile is an aprotic polar solvent with strong solubility. It can be used as a solvent for spinning, coatings, resins and certain organic metals; as a solvent for extracting butadiene from petroleum products; from Separation of allene, isoprene, propylene, etc. from hydrocarbon fractions; extraction agent for extracting fatty acids from vegetable oils; organic electrolyte for batteries; in addition, it is also used as medicine (vitamin B1), spices, and fertilizer synergists (triazine) and other raw materials; alcohol denaturant. Toxic, oral LD503800mg/kg in rats and 200mg/kg in mice. Inhalation of vapor or percutaneous absorption can cause poisoning, ranging from anesthesia to vomiting, nausea, difficulty breathing, and even coma. The concentration of cyanide in the blood increases significantly. The maximum allowable concentration in the workplace is 40×10-6. Examples of its application are as follows:

1) Prepare an energetic polymer surface-modified aluminum powder, including the following steps: Step 1: Add anhydrous acetonitrile to a three-neck flask, add aluminum powder to anhydrous acetonitrile and stir evenly; then add Dibutyltin dilaurate and toluene diisocyanate are refluxed at 70~85°C; Step 2: Cool the product of Step 1 to room temperature and then filter with suction, rinse the filter cake with anhydrous acetonitrile, and place the filter cake in a three-neck flask , add dibutyltin dilaurate and energetic polymers, and reflux at 70~85°C; Step 3: Cool the product of Step 2 to room temperature and then filter with suction, rinse the filter cake with anhydrous acetonitrile, and dry the filter cake under vacuum. That is, aluminum powder surface-modified by energetic polymers is obtained. This method not only effectively improves the hydrophobicity and mechanical properties of the aluminum powder surface, but also increases the reactivity of the aluminum powder.

2) A method for manufacturing lithium hexafluorophosphate materials. The steps are as follows: react with anhydrous orthophosphoric acid, calcium fluoride and sulfur oxide to evaporate PF5 gas; dehydrate the evaporated PF5 gas to obtain a high-purity anhydrous PF5 product; Dehydrate diethyl ether and anhydrous acetonitrile respectively to obtain high-purity diethyl ether and anhydrous acetonitrile; add high-purity lithium fluoride to the diethyl ether liquid; add acetonitrile to the above liquid; then slowly add PF5 gas under stirring, and after the reaction is completed , pass in high-purity nitrogen and replace it until there is no PF5 gas in the container; heat and decompose the distilled product Li(CH3CN)4PF6 to obtain LiPF6; dissolve LiPF6 at room temperature to form a 1M concentration solution, which is filtered through 0.2 micron precision A clear solution was obtained; after drying, pure LiPF6 was obtained.

Main reference materials

[1] Practical Fine Chemical Dictionary

[2] CN201410048053.0 Energetic polymer surface modified aluminum powder and preparation method thereof

[3] CN201110377160.4 A method of manufacturing lithium hexafluorophosphate material using composite solvent