Thermal properties and degradation kinetics of epoxy-γ-aluminaand epoxy-zinc oxide lightweight composites

摘要

Lightweight composite materials are the gold standard in aeronautical and aerospace applications due to their strength and low mass. Totransport higher payloads and reduce launching costs, nanosatellites, an excellent option for space exploration due to their lightweightstructures, are migrating to composite materials. Nanosatellites, also known as CubeSats, must resist high thermal radiation loads whileworking in orbit. Polymer-based composite materials maintain low mass and the incorporation of reinforcing ceramic fillers contributes toincreasing radiation and heat resistance, meeting both requirements. In this work, the effects ofγ-alumina (Al2O3) and zinc oxide (ZnO)micro- and nanoparticles on the thermal properties and degradation kinetics of epoxy-based composites were investigated. The effectivethermal conductivity improved up to 17.8 % for epoxy/γ-Al2O3and 27.4% for epoxy/ZnO. The effective thermal diffusivity values showa monotonic decreasing behavior as a function of the particle concentration for the epoxy/γ-Al2O3composites while for the epoxy/ZnOcomposites, no correlation on the effective thermal diffusivity values with the ZnO-content was observed. Both oxide-based ceramic fillersincrease the thermal stability of epoxy up to 250?C; however,γ-Al2O3decreased the maxima decomposition temperature of the epoxymatrix by 6?C. Zinc oxide did not affect the maxima decomposition temperature but decreased the activation energy of epoxy by 45%. Theseresults provide a feasible manufacturing method for epoxy-based composite materials (i.e., nanosatellites) where efficient heat transfer, heatresistance, and low mass are required.