ECTFE

ECTFE (ethylene chlorotrifluoroethylene) was designed to provide chemical resistance in heavy duty corrosion applications. It is a partially fluorinated polymer (a fluoropolymer), semi-crystalline and can be processed in the melt. Chemically it is a copolymer of ethylene and chlorotrifluoroethylene. It is marketed under the brand name Halar ECTFE by Solvay Specialty Polymers, a subsidiary of Solvay. ECTFE (ethylene chlorotrifluoroethylene) was designed to provide chemical resistance in heavy duty corrosion applications. It is a partially fluorinated polymer (a fluoropolymer), semi-crystalline and can be processed in the melt. Chemically it is a copolymer of ethylene and chlorotrifluoroethylene. It is marketed under the brand name Halar ECTFE by Solvay Specialty Polymers, a subsidiary of Solvay. Since its introduction in 1970, ECTFE has been used in industries where corrosion resistance is needed. It is resistant to acids at high concentrations and temperatures, caustic media, oxidizing agents and many solvents. It is said to have similar chemical resistance to PTFE. A chemical resistance table based on immersion tests is available. Permeation of large molecules is usually rather slow in fluoropolymers and thus not relevant in the final application. Small molecules, however, may permeate through the polymer matrix in a relevant time. In lining or coating applications, the permeation of certain small molecules determine the lifetime of anticorrosion protection. H2O, O2, Cl2, H2S, HCl, HF, HBr, N2, H2, CH3OH, etc. are relatively mobile in a polymer matrix and lead to measurable effects. In particular in lining and coating applications, the permeation resistance is necessary as permeating species may attack the underlying mechanical layers, such as fiber reinforced plastic or steel. This high permeation resistance to small molecules is a consequence of the free volume occupied by the chlorine atom on the polymer chain. ECTFE has a wide continuous usage temperature range between typically –76 °C and +150 °C (–105F to +300F). It has good impact resistance and a Young's modulus in the range of 1700 MPa (see suppliers website) allowing for self standing items and pressure piping systems. ECTFE offers high impact strength even in cryogenic applications. ECTFE shows good fire resistance with a limiting oxygen index of 52%. This is between the fully fluorinated polymers PTFE, PFA and FEP with a limiting oxygen index of 95% and other partially fluorinated polymer like PVDF with a limiting oxygen index of 44% and ETFE with a limiting oxygen index of 30%. ECTFE has good electrical insulator properties, i.e. high resistivity and a low dielectric constant as well as a low dissipation factor allowing its use for wire and cable primary and secondary jacketing. Similar to other fluoropolymers, ECTFE has good UV resistance, in particular against UV-A and UV-B allowing its use for outdoor applications. ECTFE films can be transparent. Specialty ECTFE films Press release UV blocking Halar ECTFE film provide transparency and UV protection for underlying layers.