EUROPEAN CONGRESS AND EXHIBITION ON ADVANCED MATERIALS AND PROCESSES - EUROMAT 2021

Carbon-based nanomaterials have been proven to be cutting-edge filler materials with advanced thermal and electrical properties, while their nanodimensions facilitate the development of defect—free mechanically robust crystal structures. Their strong hexagonal sp2 lattice allows free electron mobility in plane as well as thermal transport. In particular, carbon nanotubes (CNTs) and graphene, are ideal to add multifunctionality to reinforced composites. In this work, two applications are investigated, i.e., a) functional thermoplastic materials with self-healing properties and application in leisure and every-day life, and b) functional thermoset materials with application on industrial heat management devices with complex architectures, such as heat sinks manufacturing.
The development of these composites covers the need for sustainable, cheap, and re-/up-cyclable composites with advanced thermal functionality. In the first case, Thermoplastic polyurethane (TPU) is reinforced with graphene nanoplatelets (GNPs) and CNTs and self-healing was demonstrated. Due to the high resistance of the polymer matrix, a high portion of electric energy is converted to thermal energy. Local temperature is monitored by using an infrared camera and can reach up to 160oC, and induces local melting and annealing of the TPU matrix. In the case study of a 3D-printed specimens with the TPU masterbatch formulations enriched in GNPs and CNTs, self-healing properties are demonstrated, both in the produced 3D filament and printed parts. Thus, any wear damage will be viable for the nanocomposite and consequently the life cycle will be extended. On the other hand, epoxy-based composites suitable for heat-sink application are also reinforced with GNPs and CNTs to fabricate complex and miniaturized structures. The successful demonstration of enhanced dissipation of heat is realized by achieving composite thermal conductivity equal to 1.4 W/m∙K exceeding many of the published state-of-the-art results.