ИСТИНА

Graphite foil (GF) is a light-weighted carbon material widely used in manufacturing of packing materials, as a catalyst support, thermoconductive media etc. The low oxidation point of graphite foil limits its application in high-temperature processes. So, the development of graphite foil with the extended stability is of great importance. Several studies have shown the possibility to improve GF oxidation stability for 200 oC using boron and phosphorous compounds as antioxidative agents. The present work is devoted to the study of kinetics of GF oxidation. Three types of GF were considered. GF-1 contains no additives. The phosphorous additive was added to expandable graphite before exfoliation to get the GF-2 and GF-3 was obtained by spreading of the additive onto GF-1. All the samples were oxidized with a constant heating rate of 5, 10 and 20 K in air until the full combustion. Then the termogravimetric curves were analyzed using Netzsch Thermokinetics soft. It was shown, that phosphorous additive promotes the improvement of oxidation point of graphite foils at least for 180 oC. The weight loss of the GF-2 and GF-3 takes place in two steps – first the oxidation starts with a low rate until the protective layer evaporates and then graphite oxidation occurs with the same rate as in case of GF-1.