Surface engineering of waste tire-derived pyrolytic carbon black via flash-heating treatment achieves enhanced rubber...

The recycling of waste tire-derived pyrolytic carbon black (CBp) has attracted increased attention. However, the adsorbed surface organic gum layer hinders its industrial reinforcement application, and the traditional prolonged high-temperature degumming treatment caused irreversible graphitization of the carbon microstructure, resulting in significantly reduced reinforcement performance. Herein, we propose a new "flash-heating + water mist quenching" strategy to achieve a rapid degumming process while simultaneously effectively suppressing graphitization, thereby maximizing retention of the original reinforcement performance. The quenching process stabilizes the newly formed surface defects and oxygen-containing functional groups on the carbon black surface, thereby enhancing the induction forces and electronic interactions between the carbon black and rubber molecules, as verified by density functional theory (DFT) calculations. The modified carbon black-filled natural rubber (800CBpf/NR) composite achieves tensile strength of 28.81 MPa, stress at 300% elongation of 14.53 MPa, and tear strength of 88.43 kN m^-1, all of which exceed those of the commercial carbon black N660-filled NR composite. Additionally, compared with the unmodified CBpf/NR, the stress at 300% elongation of 800CBpf/NR increases by 97.7%, and the combined rubber content rises by 62.7%. This work provides a novel recovery pathway for the high-value utilization of CBp.