Properties of graphite composites based on natural and synthetic graphite powders and a phenolic novolac binder

► Model encasement material for fuel pebbles was prepared by uniaxial compression moulding. ► They featured anisotropic property behaviour due to partial alignment of the graphite flakes. ► Properties also varied nonlinearly with the ratio of natural to synthetic graphite filler. ► The lowest CTE measured was 1.2 × 10−6 K−1 and the highest thermal conductivity 30 W m−1 K−1 at 100 °C.