Herein, a facile approach for the development of effective and low-cost carbon precursors from acrylonitrile butadiene-styrene (ABS) rubber is reported. ABS rubber with a negligible char yield can be converted into an excellent car bon precursor with approximately 54% char yield under a nitrogen atmosphere at 800°C by simple iodine doping and sub sequent heating at 110°C under an inert atmosphere. The enhanced char yield is attributed to the improved intermolecular interactions between the ABS chains caused by the formation of covalent bonds between the butadiene segments, along with the newly developed charge-charge interactions and other indiscriminate radical-radical couplings. The charges and radicals involved in these interactions are also generated by iodine doping. We believe that this study will be useful for the devel opment of low-cost carbon precursors.