2020-03-25 环球过滤分离技术网 filtrasolution3
After discovering that ethylene has good copolymerization properties with fluorinated monomers,many new fluoropolymers were developed to achieve more favorable application properties. The first fluoropolymer containing ethylene units was ECTFE, which was introduced to the market by the Italian company Ausimont in 1970. ECTFE is an alternating copolymer of ethylene and CTFE
ECTFE is prepared by the copolymerization of ethylene and CTFE at relatively low temperatures (<10 °C) in an aqueous medium using a peroxide catalyst and a halogenated solvent chain transfer agent to regulate the molecular weight .ECTFE polymer chains pack in an extended zigzag confirmation, which results in a crystallinity of 50%–60%. ECTFE has a melting temperature in the range of 220–245 °C depending on the polymerization methods. ECTFE can be used over a broad temperature range from −100 °C to 150°.
ECTFE在相对低的温度 (<10 °C)下聚合得到，用过氧化物引发剂和含卤溶剂作为链转移剂来调节其分子量。ECTFE的熔融温度在220–245 °C ，取决于它的聚合方法，可在 −100 °C to 150°的宽幅范围应用。
ECTFE can be processed by the standard processing methods for traditional thermoplastics in the range of 260–300 °C. It is readily converted into fibers, filaments, films, sheets, and wire and cable insulation. Noticeably, the molten ECTFE is corrosive and special corrosion-resistant steels are used for screw and barrel components.
As the copolymer with ethylene, ECTFE has moderate chemical resistance, flame resistance, and dielectric constant (2.6). While, it still has excellent radiation resistance, weathering resistance, and barrier properties, as well as good tensile, flexural and wear-related properties. The strength, wear resistance and creep resistance of ECTFE are significantly greater than that of PTFE and FEP. ECTFE film is the most abrasion resistant and highest tensile strength fluoropolymer film available.
The single largest use of ECTFE is the flame-resistant insulation for wire and cable applications,extensively used for aircraft, mass transit and automotive wiring. ECTFE also finds applications in chemical process equipments and components. ECTFE is used in aerospace applications, such as gaskets for liquid oxygen and other propellants, components for spacecraft and aircraft cabins,convoluted tubing, abrasion resistant braid and hose for expandable conduit for space suits.
At the end of 1999, Ausimont introduced a new family of ECTFE resins under the trademark Vatar,specifically designed to meet the requirements for plenum cable applications. ETCFE is currently manufactured by Solvay under the trademark Halar after acquiring Ausimont in 2002.