Highly enhanced thermal conductivity of TPU composites with segregated network constructed by the in-situ reduction of copper

Cu@TPU composite particles with a structure of TPU core and Cu particles shell were fabricated by in-suite reduction of Cu on the surface of TPU granules. The Cu@TPU composites were then prepared by the hot compression of the as-prepared core-shell particles. The Cu@TPU composite granules were characterized by X-ray photoelectron spectroscopy, X-ray diffraction, thermogravimetric analysis and scanning electron microscopy, which verified that the outer layer of core-shell structure was Cu particles and the connection between Cu and TPU was chemical bonding. The cross-section of Cu@TPU composites showed typical pattern of segregated structure and the surface of those was covered by a layer of Cu particles. With the stacking effect of the special location of Cu and the chemical connection between Cu and TPU, the Cu@TPU composites exhibited a high thermal conductivity of 3.2146 W/m K at 23 vol% filler loading, which was 2.6 times to that of Cu/TPU composites fabricated through simple blending. The TC data of the composites were correlated with Foygel's model. In addition, the dielectric properties and electrical conductivity of the composites were measured. (c) 2023 Elsevier B.V. All rights reserved.