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Polychlorotrifluoroethylene (PCTFE) is a very high-performance fluoropolymer with very good chemical, thermal and mechanical properties. It is a semi-crystalline thermoplastic resin based on polymerization of chlorotrifluoroethylene (CTFE) monomer. PCTFE has a special combination of features that make it ideal for high performance use cases in industries such as chemical processing, aerospace and electronics.
Basic Properties
- Crystallinity: semi-crystalline polymer, crystallinity is 40% to 80%.
- Glass transition temperature: 71 to 99 °C.
- Melting point: 211 to 216 °C.
- Decomposition temperature: When the temperature exceeds 310 °C, PCTFE decomposes in the presence of O2.
Performance Characteristics
- Chemical Stability
The fluorine and chlorine content make PCTFE chemical corrosion and chemical inert. Only molten alkali metals or chlorosulfonic acid can corrode PCTFE, which can be used to manufacture corrosion-proof pumps and valves, and transfer corrosive media like acids and alkalis as strong as < 100 °C.
- Heat Resistance and Low Temperature Resistance
PCTFE will hold stability in a range from -196 °C to 300 °C, ideal for extreme temperature conditions. Further, as a low temperature polymer, PCTFE is particularly low-temperature resistant and creep resistant in liquid nitrogen, liquid oxygen and liquefied natural gas. This is why PCTFE is also a widely applied lining material in pipelines of liquefied natural gas, liquid oxygen and liquid nitrogen, as well as liquid fuel seals, cryogenic valves, etc.
- Mechanical Properties
PCTFE has high tensile strength, toughness, and low deformation rate, making it suitable for applications requiring high strength and durability. The mechanical behavior of PCTFE can be tuned by manipulating the crystallinity and molecular weight. We discuss this in detail later.
- Electrical Insulation and Dielectric Properties
PCTFE is broadband in low dielectric constant and dielectric loss and thus the ideal material for high-frequency communication applications. Since PCTFE is electrically insulating, it can be coating materials on electrical wiring, plug-ins, and circuit boards in wet conditions.
- Barrier Properties
PCTFE is very good water vapour barrier, its water vapour permeability is less than 0.171 kg/(m2·h). It is mostly employed as a packaging film for aircraft, defense, medical devices, electronics and other industries and holds a 75% market share of PCTFE.