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Tn recent years, graphene/polyurethane nanocomposites have attracted much attention due to their superior comprehensive properties. Incorporating graphene or its derivatives into I〉U matrix could significantly improve the physical mechanical, thermal, electromagnetic and other properties, which meets the special requirements of high-performance and multi-functional polymer composites. Tn this paper, the functional modification methods of graphene nanosheets, including covalent modification and non-covalent modification were first introduced. Furthermore, the fabrication processes of graphene/poly urethane nanocomposites, including in-situ polymerization, solution blending, melt blending, aqueous (latex) blending, etc., were briefly introduced. The recent research progress of graphene/poly urethane composites in mechanical, electrical, dielectric, thermal, gas barrier, flame retardant, electromagnetic interference shielding and corrosion resistant properties were all reviewed in detail. The future challenges and development prospects of high-performance graphene/poly urethane nanocomposites were also prospected. [ABSTRACT FROM AUTHOR]

In this paper, graphene from inexpensive sucrose is prepared by in-situ growth directly on the Cu flakes, and Cu matrix materials(Cu-MMs) with various in-situ graphene content is fabricated by hot-press sintering. The effect of sucrose content on the phase composition, microstructure and thermal properties of bulk Cu-MMs is studied by XRD, SEM, thermal conductivity (TC) and coefficient of thermal expansion (CTE). Results obtained indicate that after the heat treatment at 800 ℃ for 15 min under the H2/Ar gas flow, the in-situ growth of graphene on the surface of Cu flakes occurs. The graphene exhibits good attachment to Cu matrix and homogenous dispersion, which is beneficial for thermal properties of Cu-MMs. With 0.73 vol% grapheme, the TC of Cu-MMs reaches 339 W/(m·K), which is higher by 19.3% than that of Cu, and meanwhile CTE is far lower than that of Cu from 50 ℃ to 300 ℃. [ABSTRACT FROM AUTHOR]

With the development of electronics？ spaceflight and aviation, the integrated circuit develops rapidly, but it is often accompanied by the problem of heat dissipation ？ which affects the efficiency and the life of instruments. Considering the weight, corrosion resistance？ processing technology and cost？ polymer composites are the most promising materials for thermal conductivity. However, the inherent thermal conductivity of polymers is very low, so improving the thermal conductivity of polymers is very important for their applications in these fields ？ which has become a very important research topic in the past two decades. Tn this review paper, the following two aspects were mainly introduced. The micro thermal conductivity mechanism of polymers was analyzed and summarized from three aspects of molecular chain morphology ？ chain structure and inter-chain coupling. The main research progress in the thermal conductivity of graphene-filled polymer nanocomposites in recent years and the research challenges in the future were highlighted. [ABSTRACT FROM AUTHOR]