ZrW2O8-doped epoxy as low thermal expansion insulating materials for superconducting feeder system

Epoxy resin insulating materials used in superconducting feeder system of fusion device are required to be low thermal expansion coefficient (TEC). In this paper, negative thermal expansion (NTE) material ZrW2O8 filled epoxy resins were fabricated. To improve the dispersion of fillers in epoxy matrix, plasma polymerization was performed on the surface of ZrW2O8 powders. Transmission electron microscope (TEM) and surface wettability analysis were performed before and after the surface modification of ZrW2O8 powders. The TEC of ZrW2O8/epoxy composites were measured from 77 K to room temperature. The results show the doping of ZrW2O8 can significantly reduce the TEC of epoxy resins. The sedimentation rate of ZrW2O8 before and after modified in epoxy was compared by density measurement. It can be seen that the ZrW2O8 surface modified by plasma polymerization can enhance its dispersion properties in epoxy matrix.

► Tailored thermal expansion epoxy composites were fabricated by filling ZrW2O8.
► Plasma assisted surface modification of ZrW2O8 particles were performed.
► Low temperature thermal expansion coefficients of composites were investigated.
► We find dispersion of ZrW2O8 in epoxy was enhanced after plasma coated.
► Thermal expansion coefficients of composites were decreased.