Polychlorotrifluoroethylene mechanical properties

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. 

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],... 

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. 

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