1,1-difluoroethane
1,1-difluoroethane
CAS: 75-37-6
Molecular Formula: C2H4F2
1,1-difluoroethane - Names and Identifiers
| Name | 1,1-difluoroethane |
| Synonyms | HFC152a FC-152A HFC-152A HFC-152a freon 152a DIFLUOROETHANE 1,1-Difluorethan 1,1-DIFLUOROETHANE 1,1-difluoroethane ETHYLIDENE FLUORIDE ETHYLIDENE DIFLUORIDE 1,1-Difluoroethane (FC-152a) |
| CAS | 75-37-6 |
| EINECS | 200-866-1 |
| InChI | InChI=1/C2H4F2/c1-2(3)4/h2H,1H3 |
1,1-difluoroethane - Physico-chemical Properties
| Molecular Formula | C2H4F2 |
| Molar Mass | 66.05 |
| Density | 0.966 |
| Melting Point | -117 °C |
| Boling Point | -25 °C |
| Water Solubility | 5.37g/L(0 ºC) |
| Solubility | Soluble 1 in 357 parts of water at 25°C. |
| Vapor Density | 2.28 (vs air) |
| Refractive Index | 1.2434 |
| Physical and Chemical Properties | Gas with a slight ether taste. melting point -117 ℃ boiling point -24.95 ℃ relative density 0.9583/L |
| Use | Used as a Freon substitute, refrigerant, aerosol propellant |
1,1-difluoroethane - Risk and Safety
| Risk Codes | R11 - Highly Flammable R12 - Extremely Flammable |
| Safety Description | S16 - Keep away from sources of ignition. S33 - Take precautionary measures against static discharges. S36 - Wear suitable protective clothing. S38 - In case of insufficient ventilation, wear suitable respiratory equipment. |
| UN IDs | UN 1030 2.1 |
| WGK Germany | 1 |
| RTECS | KI1410000 |
| Hazard Note | Flammable |
| Hazard Class | 2.1 |
| Toxicity | LC50 inhalation in mouse: 977gm/m3/2H |
1,1-difluoroethane - Upstream Downstream Industry
| Raw Materials | Calcium carbide Hydrofluoric Acid vinyl chloride pressure tin with 250 ml ~225 G net Hydrofluoric Acid acetylene |
1,1-difluoroethane - Nature
Open Data Verified Data
colorless and easily liquefied gas. Boiling point -24. 95 °c. Melting Point -117 °c. Density 0.9583/L. Viscosity 0. 219 × 10-3 Pa -s. The critical temperature was 113. 45 ℃. The critical pressure is 4.54MPa. The loss of hydrogen fluoride at high temperatures generates vinyl fluoride. Easy chlorination into chlorodifluoroethane, dehydrochlorination into vinylidene fluoride
Last Update：2024-01-02 23:10:35
1,1-difluoroethane - Use
Open Data Verified Data
an important raw material for the preparation of vinyl fluoride and vinylidene fluoride, can also be used as a refrigerant, aircraft propellant.
Last Update：2022-01-01 10:14:22
1,1-difluoroethane - Safety
Open Data Verified Data
The toxicity was small.
Last Update：2022-01-01 10:14:23
1,1-difluoroethane - Reference Information
| NIST chemical information | information provided by: webbook.nist.gov (external link) |
| EPA chemical substance information | information provided by: ofmpeb.epa.gov (external link) |
| synthesis method | the production technology development of difluoroethane started earlier and has formed a certain production scale. In foreign countries, the large-scale production companies of difluoroethane are DuPont Company of the United States, Solvay Company (The Netherlands), Japan, Germany, the former Soviet Union, China, the United States and Japan have large-scale production units. Production methods according to different raw materials are mainly divided into the following three kinds: (1) with vinyl chloride as raw material synthesis of difluoroethane;(2) with acetylene as raw material synthesis of difluoroethane;(3) difluoroethane was synthesized from ethyl chloride. The starting materials for the production of difluoroethane from vinyl chloride are vinyl chloride and anhydrous hydrofluoric acid. The reaction process includes two reaction processes: Addition and substitution. The specific reaction formula is as follows: FIG. 2 is a chemical reaction scheme for the production of difluoroethane by a vinyl chloride process. vinyl chloride belongs to the ethylene type halogenated olefin, and the halogen atom is directly attached to the unsaturated SP2 hybrid carbon atom. Under normal circumstances, it is not easy to occur nucleophilic substitution reaction, so in the vinyl chloride fluorination reaction, because there are double bonds in the vinyl chloride molecule, the first step is only an addition reaction, the reaction is greatly accelerated in a polar medium and in the presence of the catalyst. CH3-CHClF of the vinyl chloride produced in the first step of the fluorination reaction is a halogenated alkane, each haloalkane having the same alkyl group, whose activity is: RI>RBr>RCl>RF. In the fluorination reaction of vinyl chloride, CH3-CHClF is substituted by HF to CH3-CHF2. The substitution reaction of CH3-CHClF and HF belongs to SN1 type and should be carried out under strong polar conditions, so it is very important to select an efficient catalyst. According to the data, there are many kinds of catalysts for liquid phase fluorination of vinyl chloride, such as ferric chloride, aluminum trichloride, titanium tetrachloride, antimony pentachloride, tin tetrachloride, etc., and some high purity acids are also commonly used to adjust the reaction system. |
| production of difluoroethane from acetylene and dichloroethane | (1) using acetylene as raw material The raw material for producing difluoroethane by this method is acetylene and anhydrous hydrofluoric acid, and the specific reaction formula is as follows: CH = CH + 2HF → CH3CHF2. In general, AlF3 is used as a catalyst to synthesize HFC-152a by gas phase reaction. The reaction temperature is high, at 200~280 C, the control of the reaction time is very important, and the conversion rate can reach 96% ~ 98%. difluoroethane (HFC-152a) was synthesized from acetylene and HF with low cost and easily available raw materials. At present, two processes have been formed: liquid phase method and gas phase catalytic method. In China, the liquid phase method for the production of difluoroethane has more than 30 years of history, the collection of a lot of experience. Gas-phase manufacturing process Research work started late, not too mature. From the technical level, the two manufacturing methods have their own advantages, but in terms of catalyst life, waste catalyst discharge treatment, equipment corrosion, environmental pollution, operational flexibility and raw material consumption, it seems that the gas phase method is slightly better than the liquid phase method. (2) using dichloroethane as raw material It has been reported that under the conditions of Lewis acid catalyst and FeCl3 co-catalyst, hydrofluoric acid and 1, method for synthesis of HFC-152a by fluorination of 2-dichloroethane in liquid phase. The Lewis acid is a compound based on tin, antimony, titanium, molybdenum, tungsten, niobium or tantalum. The reaction temperature of this method is 30~180 deg C, the pressure is 0.2~5 MPa. A method for the preparation of 1, 1-difluoroethane (HFC-152a) has been reported in the literature. The catalyst used In the process is impregnated with a catalyst selected from the group consisting of As, Sb, Al, Tl, In, V, Nb, Ta, Ti, activated carbon of a strong Lewis acid fluorination catalyst of halides of Zr and Hf, which is activated by anhydrous hydrogen fluoride gas and chlorine gas; The reaction raw material is hydrogen fluoride with 1, 2-dichloroethane or 1, halogenated hydrocarbon of 1-dichloroethane at a reaction temperature of 40-400 °c and a reaction pressure of 0.0689-about 1.24MPa. |
| used as refrigerant and blowing agent | (1) difluoroethane (HFC-152a) can be used alone as refrigerant, such as China Wanbao Group in HFC-152a on the production of small quantities of refrigerator. However, due to the flammable and low toxicity properties of HFC-152a, more than HFC-152a of them are used in combination with other components as refrigerants to replace difluoro-dichloromethane (CFC-12) and difluoro-chloromethane (HCFC-22), which are the refrigerants that cause serious damage to the atmospheric ozone layer. And CFC-502, etc. At the same time, due to the restriction of the use of 1,1,1, 2-tetrafluoroethane (HFC-134a) in Europe in recent years, many Mixed refrigerants made up of HFC-152a in combination with other components are also used in place of tetrafluoroethane (HFC-134a). (2) used as a foaming agent: in view of the need of environmental protection, chlorofluorocarbons, which have always been used as foaming agents, have obvious ODP and will be gradually eliminated; hydrocarbon blowing agents are defined as volatile organic compounds (VOCs) with actinic reduction, the use of which is also subject to strict restrictions; Therefore, difluoroethane (HFC-152a) is often used as trichlorofluoromethane (CFC-11), CFC-12 and other foaming agents of the final product and was developed. |
| Other fields of application | 1, difluoroethane HFC-152a by light chlorination to produce 1, 1-dichloro-1-fluoroethane (HCFC-141b). The ozone destruction coefficient HCFC-412b is also very small as 0.06, is one of the candidate alternatives of refrigerant, foaming agent, aerosol propellant, and is an important monomer of synthetic fluorine rubber, fluorine plastic-vinylidene fluoride indispensable raw material. The raw material of PVDF Resin is HFC-152a, which is represented by U. S. Pnnwald company abroad, Shanghai Institute of Organic auxiliary materials, Chengguang Chemical Research Institute of the Ministry of Chemical Industry and Zhejiang Research Institute of Chemical Industry in China. The output of PVDF Resin abroad accounted for the second place of fluororesin, and with the development of domestic research and application of PVDF Resin in recent years, HFC-152a of the demand has increased year by year. 2, for heat pump working fluid: HFC-152a of the mixed can be used as heat pump working fluid. Patent CN1613956 discloses HFC-152a and 1,1,1,3,3, 3-hexafluoropropane (HFC-236fa) the two substances are physically mixed into corresponding mixed working fluid at normal temperature according to the specified ratio, which is suitable for medium-high temperature heat pump units. The mixed working fluid does not destroy the ozone layer and meets the requirements of environmental protection, the thermal parameters are suitable and the cycle performance is excellent. 3. In addition to the above application fields, difluoroethane HFC-152a has long been used as a solar cell industry and a surface treatment agent. Some of our factories and scientific research units to start the application, early all need to import, is now produced by Zhejiang Institute of Chemical Industry refined HFC-152a. In addition, there are HFC-152a used as a protective atmosphere, For example, the patent CN1587424 discloses a magnesium alloy melting method with difluoroethane HFC-152a as the protective atmosphere, and the use of HFC-152a as the protective atmosphere can effectively prevent the oxidation and combustion of magnesium alloy in the melting process, which has good protection effect, low price and lower greenhouse effect. |
| Application | used as an important raw material for preparing fluoroethylene and vinylidene fluoride, such as fluoride substitute, refrigerant, aerosol propellant, etc, also used as aircraft propellant, refrigerant. By mixing the product with Freon -12 (26.2:73.8 by weight), a refrigerant having a greater freezing capacity can be obtained. used as Freon substitute, refrigerant, aerosol propellant |
| production method | acetylene is produced by reacting calcium carbide with water in an Acetylene generator, and impurities are removed by washing with water and absorption with sodium hypochlorite. The purified acetylene was sufficiently dried to enter the fluorination reactor. In the presence of sulfonyl fluoride, Acetylene reacts with hydrogen fluoride to produce crude difluoroethane. The crude Difluoroethane is compressed and fractionated to obtain the finished product. The product can also be obtained from the reaction of 1, 1-dichloroethane with hydrogen fluoride. |
| category | hazardous gas |
| toxicity grade | low toxicity |
| Acute toxicity | inhalation-rat LCL0:64000 PPM/4 hours; Inhalation-mouse LC50:977 mg/m3/2 h |
| explosive hazard characteristics | high thermal explosion |
| flammability hazard characteristics | non-flammable at room temperature; Flammable at high heat; Toxic fluoride gas from combustion |
| storage and transportation characteristics | The warehouse is ventilated and dried at low temperature; It is light and light unloading; It is stored separately from the combustible material |
| fire extinguishing agent | water mist, carbon dioxide, carbon tetrachloride |
| Occupational Standard | TWA 200 mg/m3; Tel 500 mg/m3 |
| DOT Classification | 2.1 (Flammable gas) |
| toxic substance data | information provided by: pubchem.ncbi.nlm.nih.gov (external link) |
Last Update：2024-04-09 20:49:11
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Raw Materials for 1,1-difluoroethane
Calcium carbide
Hydrofluoric Acid
vinyl chloride pressure tin with 250 ml ~225 G net
Hydrofluoric Acid
acetylene
Hydrofluoric Acid
vinyl chloride pressure tin with 250 ml ~225 G net
Hydrofluoric Acid
acetylene