Knowledge of the chemical composition of plasma is necessary for calculations and modeling in thermal plasmas. Indeed, from the knowledge of this composition we can calculate the thermodynamic properties, the transport coefficients and the radiative properties of a plasma medium. In this work, we propose to study at thermodynamic equilibrium the influence of pressure and of the PMMA polymer on the composition of the plasma of the Air - PMMA gas mixture. We are studying in particular the evolution of the density of the species created in this plasma as a function of temperature (5000 - 30000 K) and pressure (1 bar - 10 bar) for variable mixtures at thermodynamic equilibrium. When we want to take into account a large number of chemical species in the plasma, two main methods are usually used, one is based on the law of mass action and the other on the minimization of Gibbs’ free enthalpy. In our study, we used the mass action law method to calculate the composition of plasma. The results obtained show that when the plasma is in thermodynamic equilibrium the densities of the different species present in the plasma are only a function of the temperature, the pressure and the percentage of the polymer in the mixture.

Electric Arc, Plasma, Chemical Composition, Density, Polymer, Circuit Breaker