PROCESS FOR THE PREPARATION OF CARBON FIBERS PRECURSOR OR CARBON SLIT TAPES PRECURSOR

The present invention relates to a process for the preparation of a carbon fiber precursor or a carbon slit tape precursor, comprising the steps of: a) mixing at least one polyolefin or at least one polystyrene, with at least one additive (a1) selected from the group comprising carbon nanotubes, carbon fibers, carbon black, graphene, nanographene, graphite, expanded graphite, nanographite, fullerenes, and mixture thereof; and/or or at least one additive (a2) selected from the group comprising calcium carbonate, sodium carbonate, lithium carbonate, sodium bicarbonate, potassium bicarbonate, magnesium carbonate, alumina, hydrated alumina, magnesia, silicon aluminum oxynitride, borosilicate, silicon carbide, boron carbide, titanium carbide, boron nitride, boron nitride nanotubes, boron nitride nanosheets, silicon nitride, aluminum nitride, titanium nitride, titanium diboride, aluminum dodecaboride, diatomite, feldspar, gypsum, hormite, kaolin, mica, nepheline syenite, perlite, phyrophyllite, smectite, talc, vermiculite, zeolite, calcite, wollastonite, calcium metasilicate, calcium sulfate, aluminum silicate, silicon dioxide, titanium dioxide, clay (such as kaolinitic clay, a calcined kaolinitic clay, exfoliated clay), dolomite, and mixtures of two or more thereof; b) forming the mixture obtained in step (a) into a fiber or a slit tape having at least one dimension ranging from 500 nm to 200 μm; and c) subjecting the fiber or slit tape obtained in step (b) to a thermal treatment in the presence of at least one inorganic acid; thereby obtaining a carbon fiber precursor or a carbon slit tape precursor. The present invention also relates to the carbon fiber precursor or carbon slit tape precursor obtained with said process. The present invention also relates to a process for preparing carbon fibers or slit tapes by thermal graphitization treatment of said carbon fiber precursor or slit tape precursor. La présente invention concerne un procédé de préparation d'un précurseur de fibre de carbone ou d'un précurseur de bandelette découpée de fibre de carbone, comprenant les étapes consistant à : a) mélanger au moins une polyoléfine ou au moins un polystyrène, avec au moins un additif (a1) choisi dans le groupe comprenant les nanotubes de carbone, les fibres de carbone, le noir de carbone, le graphène, le nanographène, le graphite, le graphite expansé, le nanographite, les fullerènes, et un mélange de ceux-ci ; et/ou au moins un additif (a2) choisi dans le groupe compr