A novel high thermal conductivity powder coating based on synergistic reinforcement of heat conduction and infrared heat radiation

Abstract

Addressing the limitations of conventional organic polymer coatings in thermal management, this study developed an eco-friendly micro-3D expanded graphite powder (MEGP) protection coating that integrates exceptional heat conduction and heat radiation. In terms of thermal conductive filler selection, expanded graphite (EG) with a micro 3D structure was selected as the filler framework of the composite coating, and a self-assembled functional filler (MEG) was obtained after modification with an as-prepared corrosion inhibitor of a Schiff base–Ce complex (SP), which formed a 3D conductive network in the coating by electrostatic self-assembly. The unique architecture endowed MEGP with a remarkable thermal conductivity of 2.6 W m⁻¹ K⁻¹, 12-fold higher than that of pure epoxy (common resin for anti-corrosion coatings) and high infrared emissivity (0.95–0.98 at the full spectrum range of 2.5–25 μm), synergistically enhancing heat dissipation through dual conduction and radiation mechanisms. Finite element simulations confirmed superior thermal management performance. Simultaneously, the MEGP coating exhibited robust adhesion (10.4 MPa) and impact resistance (100 cm). Moreover, the impedance modulus of the coating at 0.01 Hz remains above 10⁸ Ohm cm² during 90 d immersion in a 3.5 wt% NaCl solution, benefiting from the Schiff base–Ce complex. The structure–property relationships between the 3D network architecture and multifunctional performance were elucidated by a systematic study. This novel design provides a new method for preparing functional integrated coatings with high thermal conductivity.

Keywords: Thermal conductivity; Infrared emissivity; Schiff base; Anti-corrosion; Powder coating.