Study On The Expansion Model And Reaction Kinetics Of Expandable Graphite

According to the market present situation and development trend of expansible graphite (EG), The paper selects the commercial sulfuric, nitric EG and the sulfur-free EG which was prepared in the laboratory as the research objects; the thermal expansion model and thermal decomposition reaction kinetics of EG as the core content. Then we study its application in the field of infrared/millimeter wave smoke agent.First of all, the optimum dosage of reactants and the optimum reaction parameters for the preparation of sulfur-free EG are determined on the basis of the expansion volume, and the apparent, internal structure and composition of the three kind of EG and expanded graphite were analyzed by using analytical means such as SEM, XRD, TG/DSC, FTIR. Then, the paper obtains the activation energy of the three kind of EG through the TG-DTG curves and the classic multiple scan rates methods KAS method and FWO method.After that, according to the linear expansion of expandable graphite and the energy balance, mass balance equation and the Griffith crack theory, a simple expansion model is established. The model is verified by the experiment, and is confirmed the feasibility by comparing the results of high-speed photography and the model.Finally, the application of EG in the anti-IR/millimeter wave smoke is studied. The initial formulation of smoke agent is determined by the burning experiment, and is optimized by using the orthogonal design method. Then, the paper completes the field experiment to measure the optimal formula. The experimental result shows that the formula has attenuation of 3mm and 8mm wave, especially in the 3mm wave, and it also has good interference effect of infrared.