Self-Healing Graphene–Polyurethane Nanocomposite with High Thermal Conductivity

Reliable operation of high-frequency electronic devices is enhanced by high-performance thermal management materials. However, damage to thermally conductive composites caused by thermal stress and mechanical loading during operation significantly impairs their cooling efficiency for the devices. Herein, a nanocomposite integrating both thermal conduction and self-healing capabilities was achieved through the noncovalent bonding network formed between polyurethane (PU) and graphene (Gra) nanosheets. In the Gra orientation structure generated by the regulation of hot pressure, the pyrene ring on PU not only created π–π interaction with Gra but also cooperated with the pyrimidinone group to form π–π and quadruple hydrogen bonding interaction between polymer chains. The interfacial heat transfer and self-healing capabilities conferred by the noncovalent bonding network enable the nanocomposite to achieve in-plane thermal conductivity (λ∥) of up to about 6.0 W m–1 K–1, with healing efficiencies of λ∥ exceeding 96% even after scratch repair and remodeling. Molecular dynamics simulations further confirmed the role of noncovalent bonds as the interfacial structure by analyzing the interfacial heat transfer behavior between PU and Gra. The construction of nanocomposites with integrated self-repairing and heat dissipation functionalities injects perspectives into the design of advanced multifunctional thermal management materials.