2021-02-01
Synthesis of vinylidene chloride
Vinylidene chloride, also known as 1,1-dichloroethylene (VDC). According to the process characteristics, there are three production methods of vinylidene chloride: 1,1,2-trichloroethane alkali dehydrochlorination method, methyl chloroform hot cracking dehydrochlorination method and 1,1-dichloroethane hot chlorination method; according to the raw material route, there are four methods: vinyl chloride chlorination method, vinyl chloride hydrochlorination method, 1,2-dichloroethane chlorination method and ethane chlorination method.
1.1 1, 1, Alkaline hydrolysis of 2-trichloroethane
Using vinyl chloride as starting material, 1,1,2-trichloroethane was synthesized by the reaction of vinyl chloride with chlorine. The catalyst used in the reaction was iron. In fact, the reaction can be carried out without catalyst, with high yield, simple equipment, less investment and low cost. Vinylidene chloride can be obtained by the reaction of 1,1,2-trichloroethane with alkali or pyrolysis.
1,1,2-trichloroethane was obtained by substituting 1,2-dichloroethane for chlorination, and then 1,1,2-trichloroethane was hydrolyzed with 1,1,2-trichloroethane to prepare vinylidene chloride. Using 1,2-dichloroethane as raw material, this method is one of the main methods used in the world to produce vinylidene chloride. This method is connected with the production of 1,1,1-trichloroethane, and is also one of the industrial methods to produce 1,1,1-trichloroethane. In this method, 1,2-dichloroethane and chlorine gas are chlorinated at 100 and 110 ℃, and the proportion of 1,2-dichloroethane is required to be greatly excessive. The reaction produces a mixture of 1,1,2-trichloroethane,1,2-dichloroethane and polychloride. After separation, 1,2-dichloroethane can be recycled and polychloride can be separated to obtain pure chlorine
1,1,2-trichloroethane. 1,1,1-trichloroethane was synthesized from the hydrogen chloride and vinylid