Polychlorotrifluoroethylene properties

More recently, modified fluoroplastics such as fluorinated ethylene/propylene copolymer, polychlorotrifluoroethylene, and polyvinylidene fluoride have been offered by DuPont, Allied Chemical, 3M, and Pennwalt respectively, to provide improved processability and mechanical strength at some sacrifice in heat-resistance, electrical properties, and chemical resistance and at prices of 3.70-7.15 these have also been finding appropriate if smaller markets. 

Polychlorotrifluoroethylene (PCTFE) has better mechanical properties than PTFE because the presence of the chlorine atom in the molecule promotes the attractive forces between molecular chains. It also exhibits greater hardness and tensile strength, and considerably higher resistance to cold flow than PTFE. Since the chlorine atom has a greater atomic radius than fluorine, it hinders the close packing possible in PTFE, which results in a lower melting point and reduced propensity of the polymer to crystallize [7]. The chlorine atom present in ethylene chlorotrifluoro-ethylene (ECTEE), a copolymer of ethylene and chlorotrifluoroethylene (CTEE), has a similar effect on the properties of the polymer. 

Polychlorotrifluoroethylene Thermoplastic polymer of chlorotrifluoroethylene. Has good transparency, barrier properties, tensile strength, and creep resistance, modest dielectric properties and solvent resistance, and poor processibibty. Processed by extrusion, injection and compression molding, and coating. Used in chemical apparatus, low-temperature seals, films, and internal lubricants. Also called PCTFE. 

The combination of properties that makes fiuorocarbons highly desirable engineering plastics also makes them nearly impossible to heat or solvent weld and very difficult to bond with adhesives withont proper snrface treatment. Fluorocarbons such as polytetraflu-oroethylene (TFE), polyfluoroethylene propylene (FEP), polychlorotrifluoroethylene (CTEE), and polymonochlorotriflnoroethylene (Kel-F) are notoriously difficult to bond because of their low surface tension and chemical resistance. However, epoxy and poly-nrethane adhesives offer moderate strength if the fluorocarbon is treated prior to bonding. 

Polychlorotrifluoroethylene (PCTFE) consists of a linear macromolecule with the following monomer unit [—CF —CF(Cl)—PCTFE possesses outstanding barrier properties to gases. 

Hoffman, J.D., Williams, G. and Passaglia, E. (1966) Analysis of alpha beta and gamma relaxations in polychlorotrifluoroethylene and polyethylene - dielectric and mechanical properties. /. Polym. Sci., C, 14, 173. 

Similar to polytetrafluoroethylene, polychlorotrifluoroethylene is not wetted by water and its mechanical properties do not change even after long-term exposure to water. Exposure to aqueous solutions of inorganic salt does not change the properties of polychlorotrifluoroethylene [32],... 

Concentrated phosphoric acid and sulfuric acid do not attack polychlorotrifluoroethylene nor do they diffuse into it. Hydrochloric acid and hydrocarbons diffuse into polychlorotrifluoroethylene without causing a change in mechanical properties [32],... 

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