Abstract:

A series of microwave absorbing and thermally conductive composites were prepared using polyvinylidene fluoride （PVDF） as a matrix resin， flaky FeSiAl and alumina （Al₂O₃） as functional fillers， and silane coupling agent as a surface modifier. The effects of filler content and coupling agent treatment on the wave absorption and thermal conductive performance of the composite samples were intensively investigated. The results indicated that when only 20 wt% of surface⁃treated FeSiAl and Al₂O₃ was incorporated as fillers， the PVDF/FeSiAl/Al₂O₃ composites exhibited good wave absorbing performance， and their lowest reflection loss value was -37.1 dB. When the contents of FeSiAl and Al₂O₃ were 20 wt% and 30 wt%， respectively， the composites obtained an increase in thermal conductivity by 168.2 % compared to pure PVDF. Through a combination of flake FeSiAl and Al₂O₃， followed by the surface treatment with a coupling agent， the wave absorption and thermal conductive performance were both improved at a low filler content.

Key words: flaky fesial, flaky alumina, polyvinylidene fluoride, wave absorption property, thermally conductive performance