Polyethylene Based Ionomers as High Voltage Insulation Materials

摘要

Polyethylene based ionomers are demonstrated to feature athermo-mechanical and dielectric property portfolio that is comparable tocross-linked polyethylene (XLPE), which may enable the design of moresustainable high voltage direct-current (HVDC) power cables, a crucialcomponent of future electricity grids that seamlessly integrate renewablesources of energy. A new type of ionomer is obtained viahigh-pressure/high-temperature free radical copolymerization of ethylene inthe presence of small amounts of ion-pair comonomers comprising amineterminated methacrylates and methacrylic acid. The synthesized ionomersfeature a crystallinity, melting temperature, rubber plateau modulus andthermal conductivity like XLPE but remain melt-processable. Moreover, thepreparation of the ionomers is free of byproducts, which readily yields a highlyinsulating material with a low dielectric loss tangent and a low direct-current(DC) electrical conductivity of 1 to 6·10~(?14) S m~(?1) at 70 ℃ and an electric fieldof 30 kV mm~(?1). Evidently, the investigated ionomers represent a promisingalternative to XLPE-based high voltage insulation, which may permit to easethe production as well as end-of-use recycling of HVDC power cables bycombining the advantages of thermoset and thermoplastic materials whileavoiding the formation of byproducts.