A novel method to obtain a petroleum-derived mesophase pitch suitable as carbon fibre precursor

This paper studies a novel method for the preparation of mesophase pitches suitable as carbon fibre precursors. A series of thermally treated petroleum pitches with mesophase contents ranging from 10.8 to 52.2 vol.% was obtained from pitch A-240. Separation of the phases was initially attempted by hot filtration, a suitable method for separating the phases in thermally treated coal-tar pitches. Although filtration failed for the petroleum samples, the behaviour observed led to the development of a new separation method that consists in the sedimentation of the mesophase. This method, after optimisation, yielded pitches with mesophase contents up to 97 vol.%, which were easily spun into carbon fibres of reasonable mechanical properties.