Industrial Synthesis of Vinylidene Fluoride Monomer

One process to produce VDE starts with acetylene, which reacts with 2 mol of hydrogen fluoride using a Lewis acid (BE3) as catalyst giving 1,1-difluoroethane (CEC152) [68]  

CFC152 is then chlorinated to l-chloro-l,l-difluoroethane (CEC142) [69] CH3CHF2+ CI2 CH3CC1F2-F HCl 

Subsequently, CEC142 is dehydrochlorinated, yielding vinylidene fluoride [70] CH3CCIF2 CH2=CE2+ HCl 

Another, somewhat different process, starts from 1,1,1-trichloroethane, which after dehydrochlorination gives CEC142. The second step, dehydrochlorination of CEC142, is the same. The dehydrochlorination may be done either thermally or catalytically. At any rate, the production equipment has to be made from a highly corrosion-resistant material [71]. 

Catalytic pyrolysis, which is described in [72,73], starts from 1,1,1-trifluoro-ethane and yields VDF at high conversion and purity. 

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