Molecular Dynamics Simulation of Chemical Reactions of Polytetrafluorovinyl Active Materials
In order to study the microscopic mechanism behind the unique energy release characteristics of shock-induced ignition of Al/PTFE active materials,the reaction molecular dynamics method was used to simulate the pyrolysis of PTFE matrix and the chemical reaction process of Al/PTFE.The simulation results show that free radical fragments are generated after random fracture of PTFE matrix carbon chains,and(-CF2-CF2-)is detached from the free radical chain end to produce C2F4.In the Al/PTFE system,AlFx is formed by defluorination reaction between Al and PTFE on the surface of alumi-num,and AlFx is eventually dissociated into aluminium-fluorine small molecules such as AlF3 and AlF4,while chemically induced decomposition occurs after PTFE loses F,and decomposition occurs when PTFE is lower than the pyrolysis temperature.In addition,the pyrolysis activation energy of PTFE matrix is calculated by Arrhenius formula to be 146 kJ/mol,and the activation energy of Al/PTFE reac-tion is 16.4 kJ/mol.
molecular dynamicsAl/PTFEreaction force fieldactive materialspyrolysis
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