English name：dichloromethane
chemical formula：CH2Cl2
molecular weight：84.93
CAS Login number：75-09-2
EINECSnumber：200-838-9
boiling point：39.75 ℃ at 760 mm Hg
melting point：-97 °C
Water solubility: insoluble in water
Appearance: colorless, transparent and volatile liquid
Chinese Synonyms: methylene chloride; methylenechloride; methylene chloride; methylene chloride; methylene chloride; dichloromethane; dichloromethylene; methylene chloride
Solubility:
Insoluble in water, soluble in phenol, aldehyde, ketone, glacial acetic acid, triethyl phosphate, ethyl acetoacetate, cyclohexylamine. It is miscible with other chlorinated hydrocarbon solvents ethanol, ether and N, N-dimethylformamide.
After pyrolysis, HCl and trace phosgene are produced and heated with water for a long time to form formaldehyde and HCl. CHCl3 and CCl4 were obtained by further chlorination. Colorless volatile liquid, flammable. Dichloromethane reacts with sodium hydroxide at high temperature to form formaldehyde. In industry, dichloromethane is prepared by the reaction of natural gas and chlorine gas, and purified by distillation. It is an excellent organic solvent, which is often used to replace flammable petroleum ether and ether, and can be used as dental local anesthetic, refrigerant and fire extinguishing agent. The irritation to skin and mucous membrane is slightly stronger than chloroform, so attention should be paid when using high concentration dichloromethane.
Stability: dichloromethane is more stable than its similar substances (chloroform and carbon tetrachloride) when there is no moisture at normal temperature (room temperature).
Hazardous decomposition: long term contact with water will slowly decompose to produce hydrogen chloride.
Aggregation of hazards: it will not happen.
Application of dichloromethane:
Dichloromethane has the advantages of strong solubility and low toxicity. It is widely used in the manufacture of safety film and polycarbonate. The rest is used as paint solvent, metal degreasing agent, gas smoke spray agent, polyurethane foaming agent, release agent and paint remover.
Dichloromethane, a colorless liquid, is used as a reaction medium in the pharmaceutical industry for the preparation of ampicillin, benzylpenicillin and cephalosporin. It is also used as solvent, oil dewaxing solvent, aerosol propellant, organic synthesis extractant, polyurethane and other foaming agents and metal cleaning agents in film production.
Dichloromethane is mainly used in film production and medicine in China.
