Preparation of Thermally Conductive Polymer Composites with Good Electromagnetic Interference Shielding Efficiency Based on Natural Wood-Derived Carbon Scaffolds

In the modern electronic industry, multifunctional polymer composites associated with heat removal and electromagnetic shielding are highly needed. This work reports a method to fabricate epoxy composites with high electromagnetic interference shielding effectiveness (EMI SE) and thermal conductivity (TC) using natural wood as a starting material via backfilling epoxy into wood-derived carbon scaffolds. The results showed that after carbonization at 1200 degrees C, the carbon scaffolds could be well-maintained, which could serve as thermally and electrically conductive pathways in the composites. The resultant composites at the carbon loading of 7.0 vol % possessed a high TC of 0.58 W/(m.K), an electrical conductivity of about 12.5 S/m, and an average EMI SE of 27.8 dB over the X-band at the thickness of only 2 mm. Our work proposed a promising strategy to use cost-effective and green materials to fabricate multifunctional polymer composites.