抄録
We would like to report a new method to discriminate the causes of fires by evaluating the graphitizability of electric plugs left at fire venues. This method employs heat treatment of the plug resins at 3000°C and X-ray diffraction measurement to evaluate the crystallinity of the heat treated plug resins. The principle of this method is based on the fact that the thermal history of organic materials under the influence of oxygen determines their graphitizability. Four types of samples were prepared from a poly (vinyl chloride) electric plug to simulate two cases, one where electric troubles around the plug was immediate causes of the fire (immediate case) and one where the electric plugs were passively involved by the fire (passive case). 3000°C heat treatment provided different graphitizability between the two types of samples, i.e. the immediate case sample was disordered carbon, while the passive case sample was finely ordered graphite. The finding shows that this method is a promising method to discriminate the causes of fires.