Dual interface strategies using carbon dots for fabricating thermally conductive polymers by pyrrhotite and waste plastics

The thermally conductive polymers used in modern microelectronic devices have been a hot topic around the world. Herein, we proposed a novel dual interface strategy to fabricate thermally conductive polymer with waste plastics and pyrrhotite (Pyr), and decipher the interface coupling mechanisms facilitated by carbon dots (CDs). First, through hot-pressing, the polymer composites (ABS/S@CD-Pyr) were fabricated using waste poly(acrylonitrile-co-butadiene-co-styrene) (ABS) and Pyr. The thermal conductivity (TC) of polymer composites was affected by various parameters, and the highest TC reached 1.68 W/m·K. Second, the interfacial coupling of ABS/S@CD-Pyr was elucidated via the systematical characterization and molecular dynamics (MD) simulation, and the chemical coupling (C–S and C S bonds) and nanoscale effects of CDs were mainly responsible for the reduced interfacial thermal resistance and the enhanced thermal conductivity. Third, the other critical properties of polymer composites were estimated, and ABS/S@CD-Pyr possessed good electrical resistivity, electromagnetic interference shielding performance, thermal stability, mechanical strength, thermal cycling, and water resistance. Finally, the applicability of proposed strategy was tested with various types of waste plastics, and in most cases, the TC of polymer composites was above 1.60 W/m·K. These findings would provide valuable insights into the high-value resource utilization of waste plastics and Pyr tailings. • The thermally conductive polymer using waste plastics and tailings was fabricated. • The highest thermal conductivity of polymer composites was up to 1.68 W/m·K. • Chemical coupling and nanoscale effects were main mechanism of interface coupling. • Polymer composite had electrical resistivity, thermal cycling, and other properties.