Polychlorotrifluoroethylene Polymers PCTFE and Copolymers with Ethylene ECTFE

5 POLYCHLOROTRIFLUOROETHYLENE POLYMERS (PCTFE) AND COPOLYMERS WITH ETHYLENE (ECTFE) 

Polychlorotrifluoroethylene was the first fluorinated polymer to be produced on an experimental scale and polymers were used in Germany and in the United States early in World War II. PCTFE was used, in particular, in connection with the atomic bomb project in the handling of corrosive materials such as uranium hexafluoride. 

The monomer may conveniently be produced from hexachloroethane via trichl orotrifluoroe thane 

Polymerisation may be carried out by techniques akin to those used in the manufacture of PTFE. The preparation of polymers in yields of up to 88% are described in one patent. Water was used as a diluent in concentrations of from one to five times the weight of the monomer, a gas with boiling point of -27.9°C. Solid polymers were formed with reaction temperatures of 0 0°C at higher reaction temperatures liquid polymers are formed. 

Pressures varied from 20 to 15001bf/in (0.14 to 10.5 MPa) and reaction times were of the order of 5-35 hours. Reaction promoters included peroxides and salts of persulphuric and perphosphoric acids. Activators , accelerators and buffering agents were also discussed in the patent. The process of manufacmre of Kel-F is understood to be based on this patent. 

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