pctfe

Polychlorotrifluoroethene (PCTFE or PTFCE) is a thermoplastic chlorofluoropolymerwith the molecular formula (CF2CClF)n, where n is the number of monomer units in thepolymer molecule. It is similar topolytetrafluoroethene (PTFE), except that it is ahomopolymer of the monomerchlorotrifluoroethylene (CTFE) instead of tetrafluoroethene. It has the lowest water vapor transmission rate of any plastic. PCTFE finds majority of its application due to two main properties; water repulsion and chemical stability. PCTFE films are used as a protective layer against moisture. These include, Moisture barrier in pharmaceutical blister packaging. Water vapor barrier for protecting phosphor coatings in electroluminescent lamps. The phosphor chemicals are sensitive to moisture.
To protect liquid crystal display (LCD) panels which are sensitive to moisture.

PCTFE has high tensile strength and good thermal characteristics. It is non-flammable and the heat resistance is up to 175°C. It has a low coefficient of thermal expansion. The glass transition temperature (Tg) is around 45°C. PCTFE has the lowest limiting oxygen index (LOI). It has good chemical resistance. It also exhibits properties like zero-moisture absorption and non wetting. It does not absorb visible light. When subjected to high energy radiations, like PTFE, it undergoes degradation.[18] It can be used as a transparent film.