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.