Construction of interconnected Al2O3 doped rGO network in natural rubber nanocomposites to achieve significant thermal conductivity and mechanical strength enhancement

Rubber promises to be an excellent matrix for heat dissipation composites due to its unique elasticity and flexibility. However, restricted by traditional processing approaches, it remains challenging to fabricate highperformance rubber nanocomposites with both good mechanical strength and high thermal conductivity (TC). Herein, we develop a novel GO-assisted gelation method to construct a 3D interconnected rGO@Al2O3 hybrid fillers network as efficient heat transfer path in natural rubber nanocomposite acquiring desirable performance. The as-prepared rubber nanocomposite, at a filler loading of 18.0 vol%, exhibits not only a largely increased tensile strength (25.6 MPa) but also a high TC (0.514 W/(m.K)). Owing to the construction of a highly interconnected filler network, the resulting 3D rGO@Al2O3-NR shows apparently higher TC than the nanocomposites prepared by conventional method at the same filler content. More promisingly, the filler network tends to orient perpendicular to the compressing direction at ultrahigh filler loading, causing surprisingly enhanced in-plane TC which is up to 3.233 W/(m.K) at 33.9 vol% filler content. Moreover, we can easily control electrical resistance by adjusting the mass ratio of GO to Al2O3, making the nanocomposites satisfy the use requirement of electrical insulation. This study provides a creative insight to the design of high-performance rubber nanocomposites with a bright application prospect in advanced heat dissipation materials.