FLUOROLUBE GREASE, GR-362

solid
Polychlorotrifluoroethylene (PCTFE) is more expensive than poly tetrafluoroethylene and its use is comparatively limited. The preferred commercial method of preparation of polychlorotrifluoroethylene is by suspension polymerization using procedures similar to those used for polytetrafluoroethylene. In order to obtain polymer of high molecular weight, reaction temperatures are generally kept in the range 0-40°C. Initiation is commonly by means of a redox system activated by a metal salt, e.g. persulphate - bisulphite with a ferrous salt. Average molecular weights of commercial polymers are within the range 50000-500000. Polychlorotrifluoroethylene is a white solid. Compared to poly tetrafluoroethylene, it has greater tensile strength, hardness and resistance to creep. The presence of a chlorine atom, which is larger than a fluorine atom, in the polymer does not permit such close chain packing as is possible with polytetrafluoroethylene. Thus polychlorotrifluoroethylene has a lower softening point and can be processed in the melt. Because of the lower tendency to crystallize, it is possible to produce thin transparent films by rapid quenching. The presence of chlorine in the polymer results in greater interchain attraction and accounts for the better mechanical strength of polychlorotrifluoroethylene. On the other hand, the unsymmetrical structure leads to poorer electrical insulation properties.The chemical resistance of polychlorotrifluoroethylene is very good but not as good as that of polytetrafluoroethylene. Molten alkali metals and molten caustic alkalis attack the polymer and a few halogenated solvents swell or dissolve the polymer at elevated temperatures. Polychlorotrifluoroethylene may be melt processed. Standard techniques of extrusion and injection moulding may be used but careful temperature control is required since degradation occurs at processing temperatures, which are normally in the range 230-290°C. Degradation is accompanied by development of unsaturation and may involve the following chain splitting rearrangement:The temperature range of useful performance is from about -loooe to 200°C.Polychlorotrifluorethylene finds limited use for such items as diaphragms, gaskets, electrical components and transparent windows for chemical equipment. Dispersions are used for the preparation of films and coatings.
Halocarbon oil 27 isa polymer of chlorotrifluoroethylene (CTFE). It is used to lubricate pumps in hyperbaric chambers.