What is methylene chloride?
This chemical compound has the molecular formula CH2Cl2 and exists as a colorless, volatile liquid with a sweet odor similar to chloroform. Its density is higher than water and it is completely insoluble in water. When mixed with water, it forms two phases, the upper phase being that of this compound and the lower phase being that of water.
On the other hand, this substance is soluble in most organic solvents and many organic compounds dissolve in it. The presence of such unique characteristics in it leads to the easy and convenient separation of organic compounds from the aqueous environment.
Physical and chemical properties
Some physical and chemical properties of this compound can be seen in the table below.
| Structure |  |
| Chemical formula | CH2Cl2 |
| cas no | 75-09-2 |
| Molecular weight | 93/84 g/mol |
| Other names | Dichloromethane, methylene dichloride, narcotil |
| Appearance | Colorless, volatile liquid with a sweet odor |
| Density | 326/1 g/ml |
| Melting point | 7.96ºC- |
| Point Boiling point | 6.39ºC |
| Solubility | Insoluble in water |
Method of producing methylene chloride
This compound occurs naturally in nature and can be extracted through certain methods. This method is rarely used due to the cost of the process and the lack of complete access to the required resources.
The main and most important method of preparing this material is carried out in the presence of chlorine gas and applying heat. In this method, methane or chloromethane reacts with chlorine gas at a temperature of 500-400 degrees Celsius and during this process, in addition to the main product, carbon tetrachloride, chloroform, chloromethane and also hydrochloric acid are produced as by-products. The reaction mixture is subjected to distillation and finally the desired main product is separated and prepared.
CH4 + Cl2 → CH3Cl + HCl
Following this, by chlorination of chloromethane again, this material is prepared and if the reaction continues, the above-mentioned by-products are also produced.
CH3Cl + Cl2 → CH2Cl2 + HCl
CH2Cl2 + Cl2 → CHCl3 + HCl
CHCl3 + Cl2 → CCl4 + HCl
Chemical reactions of methylene chloride
This compound reacts vigorously in the presence of alkali or alkaline earth metals and hydrolyzes to formaldehyde in the presence of an aqueous alkali solution. Alkylation reactions are functionalized from both sides, so the alkylation process is accompanied by double substitution.
Uses of Methylene Chloride
This substance has many uses in various industries, which we will examine below.
Household Uses
This substance is used in the repair and maintenance of household pipes, especially for repairing kitchen and bathroom pipes. The industrial uses of this substance are widely used in the field of pharmaceuticals and process solvents.
Production and Industrial Uses
It is widely used as a cleaning solvent in varnishes and colored coatings on hard and soft surfaces. It also mentioned the uses of this substance as a solvent in the pharmaceutical industry for the preparation of cephalosporin and ampicillin.
Drug Dispersion
This substance is used in pharmaceutical laboratories to extract active pharmaceutical ingredients from plants and foods to prepare antibiotics, steroids, and vitamins.
It is also used to quickly and effectively clean sensitive medical and pharmaceutical equipment and parts.
Food and Beverage Production
This compound is an excellent solvent in the food and beverage production and extraction industry from edible products. For example, it is used for decaffeination of coffee beans and tea leaves. It is also used to extract hops for beverages, food flavorings, and spice processing.
Transportation Industry
It is widely used to remove grease from car parts, aircraft, railroad equipment, and rail tracks. It can also be used in degreasing and lubricating products used in automotive products, for example, to remove gaskets and to prepare metal parts for a new gasket.
Automotive professionals commonly use the dichloromethane vapor degreasing process to remove grease and oil from automotive parts, automotive transistors, spacecraft assemblies, aircraft components, and diesel engines. Today, professionals can safely and quickly clean transportation systems using degreasing techniques that depend on this material.
Photographic Films
This material is used as a solvent to prepare cellulose acetate, which is the main and important part of photographic films. As cellulose acetate dissolves in this material, the cellulose acetate begins to evaporate and eventually acetate fibers appear.
Electronics Industry
This compound is used in the production of printed circuit boards in the electronics industry. This material is used to degrease the surface of the substrate foil before adding a light-resistant layer to the board.
Methylene Chloride Substitute
Solvents such as ethyl acetate, ethanol, and isopropanol are among the materials that can be considered as solvents for this material.
Global Sales and Purchase Market:
The market value of this material in 2023 was $24.4 billion and is expected to grow by 5.08% to $39.9 billion by 2032. This material is actually a solvent that has many industrial applications and is used in the adhesives, paint and coating products, pharmaceuticals, metal cleaning, etc. Many factors such as the use of this material in the construction industry, drug production, paint remover, etc. are involved in the growth of the market for this material. Of course, end users such as pharmaceutical, food and beverage industries are expected to be heavily involved in the profitability of this material.
The global market for this material is segmented into various segments based on application, end industry, and geographical region. In terms of application, paint removers held the largest market share of this material in 2022. Based on application, the medical sector held the highest share in 2022 and is expected to follow this trend until 2032. Based on geographical region, Asia Pacific dominated the market for this material in 2022. This growth is also due to the rapid expansion of the construction sector and the increasing demand for this material in China, India, Japan, and South Korea. Of course, North America also accounted for the second largest market share in 2022 and is expected to maintain this growth.
Dangers and MSDS of methylene chloride
The carcinogenicity of this substance has been confirmed by experimental data and global data. It is relatively toxic when ingested, subcutaneously, and intraperitoneally. Its effects through ingestion and inhalation include paresthesia, drowsiness, sleepiness, convulsions, euphoria, and changes in the amount of carlock. In case of direct contact with the skin, it causes severe skin irritation, and the vapors from it are also very harmful and dangerous to the eyes. Therefore, use special gloves and laboratory glasses when handling this material.
It is flammable in the range of 12 to 19% in air but is difficult to ignite. It does not form an explosive mixture with air at ordinary temperatures. Mixtures in air with methanol vapor are flammable. These explosive compounds form with an atmosphere with a high oxygen content in liquid O2, N2O4, K, Na, NaK. It explodes as a vapor when exposed to heat or flame. It reacts violently with Li, NaK, potassium tert-butoxide, (KOH + N-methyl-nitrosoura). It can decompose on contact with hot surfaces and open flames, then producing toxic fumes that are irritants and warn of their presence. When heated to decomposition, it emits highly toxic fumes of phosgene and chlorine.
Due to the flammable nature of this material, it should be stored in a cool, dry place away from heat and flammable materials. After each use, the container should be completely closed and kept away from hazardous materials.
