Propagation of a Chemical Reaction through Heterogeneous Lithium-Polytetrafluoroethylene Mixtures.

摘要

An analytical and experimental investigation of the propagation of a chemical reaction through heterogeneous lithium-polytetrafluoroethylene (PTFE) mixtures was conducted. PTFE in the form of both solid rod and resin was reacted with lithium, these reactants being initially at room temperature and under a vacuum. The reaction sample was of cylindrical geometry with the PTFE located along the longitudinal centerline. The chemical reaction was initiated at one end of the sample, and the motion of the propagating reaction front was monitored by means of thermocouples located at the lithium-PTFE interface. A two-dimensional model was developed based on the assumptions that the reaction rate controlling process was the thermal decomposition of the PTFE, that the reaction products were in the condensed phase, and that conduction was the sole mode of heat transfer. The dimensionless form of the model was solved numerically, and the predicted reaction propagation velocities were in reasonable agreement with experimental results.