Microwave Properties of Composite Films Based on Polyvinyl Chloride and Brominated Activated Carbon

Brominated activated carbon (AC/Br 2 ) powder was used as a filler in poly(vinyl chloride) (PVC) to prepare PVC‐based composite films by hot pressing. The AC/Br 2 filler was obtained by liquid phase bromination and contained both oxygen and bromine. In comparison with the unmodified AC, the AC/Br 2 was subjected to thermogravimetric analysis in air and argon and temperature‐programmed desorption mass spectrometry in vacuum, which identified carbon‐oxygen and bromine groups and showed the comparable thermal stability of AC/Br 2 and AC. XPS shows the predominance of phenolic groups among the carbon‐oxygen groups. Scanning electron microscopy and transmission electron microscopy showed preserved morphology and microstructure, while N 2 adsorption showed a microporosity decrease after bromination. FTIR analysis suggested non‐chemical interactions between PVC and AC/Br 2 . As the AC/Br 2 content in the PVC‐based composite films increases from 0.2 to 30 wt %, the electromagnetic radiation (EMR) reflection at Ka‐band microwave frequencies increases. To reduce the EMR reflection, the proposed composite films should contain a maximum of 0.2 wt % AC/Br 2 . The results indicate that the microwave properties of PVC‐based composite films can be tuned by adjusting the AC/Br 2 content.