Experimental investigation of the reaction of HCFC-22 and methane in a dielectric barrier discharge non-equilibrium plasma

A dielectric barrier discharge non-equilibrium plasma was employed to study the reaction of HCFC-22 (CHClF₂) with methane (in an argon bath gas) at atmospheric pressure and in the absence of oxygen and nitrogen. The reaction produced a fluorine-containing polymeric product, as well as gaseous species including H₂, HF, HCl, CHF₃, C₂H₃F, CH₃Cl, CH₂ClF, C₂HClF₄, CHCl₂F, CH₂Cl₂ and CCl₂F₂. While the main polymeric fraction is non-crosslinked, a small portion of the solid product is crosslinked. The polymers contain a wide range of functional groups including CH₃, CH₂, CHCl, CHF, CHClF, CHF₂, CF₂ and CF₃. The conversion level of CHClF₂ increased from 53% to 78%, with an increment in input energy density from 3 kJ L^-1 to 13 kJ L^-1. A reaction mechanism is proposed explaining the formation of gaseous as well as polymeric products.