Thermally conductive polymer composites show attractive prospects as thermal management materials in many applications such as microelectronic devices. However, traditional approaches in the preparation of thermally conductive polymer composites usually have the disadvantages of complex processes. In this study, a facile method for highly thermally conductive silicone rubber composites is reported, based on 3D interconnected graphene sponges by using an inorganic salt as a sacrificial template. The composites exhibit a high thermal conductivity of 1.50 W m⁻¹ k⁻¹ and a thermal conductivity enhancement of 752% at a very low graphene loading of 1.46 wt%. More significantly, highly thermally conductive epoxy and styrene–butadiene rubber composites are also fabricated by the same method. The composites also show excellent electrical insulating properties (>10¹³ Ω cm). Thus, this effective method is proved to be widely used for the facile fabrication of polymer composites of both plastic and rubber matrices which are thermally conductive and have excellent electrical insulating properties.

Pyrene-functionalized poly(methyl methacrylate)-block-polydimethylsiloxane (Py-PMMA-b-PDMS) copolymers were synthesized via activators regenerated by an electron transfer atom transfer radical polymerization (ARGET ATRP) method and further used to functionalize graphene oxide (GO) through the π–π interaction between pyrene and the carbon sheets. The modification efficiency of the non-covalently functionalized GO (GO@Py-PMMA-b-PDMS) particles was evaluated by studying their effects on the mechanical, optical and thermal properties of the PMMA. With incorporation of 0.05 wt% GO@Py-PMMA-b-PDMS, the tensile strength, Young's modulus, elongation at break and toughness of PMMA were increased by 23%, 54%, 117%, and 218%, respectively, showing simultaneously reinforcing and toughening effects of the functionalized GO particles; the initial decomposition temperature of PMMA increased by 11 °C from 349 °C to 360 °C; and the haze value of PMMA increased from 2.1% to 16.8%; the refractive index of PMMA varied from 1.48 to 1.51. This improvement in the physical properties of PMMA can be attributed to the homogeneous dispersion and enhanced interfacial adhesion between GO@Py-PMMA-b-PDMS and PMMA. This work demonstrates the feasibility of using GO@Py-PMMA-b-PDMS as a modifier for simultaneously improving the mechanical, optical and thermal properties of PMMA for potential organic light-emitting diodes and organic photovoltaics applications.

Novel porous polymer/graphene composite aerogels with a multiple network structure, enhanced compressive properties and high thermal conductivity are first fabricated by adsorbing water vapour, reduction, and freeze-drying procedures. The aerogels are comprised of a copolymer of monomethacrylate terminated poly(dimethylsiloxane) and glycidyl methacrylate (PDMS–PGMA), polydopamine–reduced graphene oxide (PDA–rGO), and poly(3-mercaptopropyl)methylsiloxane (PMMS). PMMS as a crosslinking agent reacts with PDMS–PGMA and PDA–rGO by the thiol-Michael addition click reaction, resulting in the formation of unique multiple networks in the aerogels. An aerogel with a low graphene loading (2 wt%) exhibits optimal comprehensive performance, i.e. a high thermal conductivity (0.816 W m⁻¹ K⁻¹), high compressive stress at 50% compression ratio (3.4 MPa) and good oil-adsorption capacities. These outstanding properties of aerogels are attributed to the multiple networks and the interconnected PDA–rGO skeleton. The aerogels have potential applications in heat radiating elements, oil/water separators and high performance materials.