The mechanochemical reaction, or ball milling, as an efficient manufacture process has been reported to make graphitic nanoplatelets (GnP) that have advantages such as low defects, easy process, control of functional groups, mass-production, low-cost, etc. Thus, in this study, first, decene-functionalized graphitic nanoplatelets (De-f-GN) were prepared with only graphite and 1-decene. The resultant De-f-GN has exceptional properties with very good dispersion into THF enabling its use as a reinforcing filler for acrylonitrile butadiene styrene (ABS) resin due to the chemical affinity. De-f-GN/ABS_X nanocomposites were made by the solution casting approach that exhibited remarkable mechanical properties and thermal stability compared with pure ABS resin. Compared to pure ABS, the tensile strength and toughness of the De-f-GN/ABS_1 are increased by 60.0 % and 107.1 %, respectively. These results demonstrate that the mechanochemical reaction is efficient and has many advantages enabling its use in application areas as a new competent filler for polymer nanocomposites.