Nonequilibrium Plasma Polymerization of HFC-134a in a Dielectric Barrier Discharge Reactor: Polymer Characterization and a Proposed Mechanism for Polymer Formation

Nonequilibrium plasma polymerization of hydrofluorocarbon HFC-134a (CF₃CH₂F) in argon bath gas has been studied in a dielectric barrier discharge reactor at atmospheric pressure and in the absence of oxygen and nitrogen. The reaction resulted in the formation of a polymeric solid fraction and the noncrosslinked properties of this material assisted in its characterization by solution state ¹³C and ¹⁹F nuclear magnetic resonance spectroscopy. Gel permeation chromatography revealed that the polymers include low (number average molecular weight, Mn values between 900 and 3000 g mol^-1) and high (Mn approximately 60000 g mol^-1) molecular weight fractions. A detailed polymerization mechanism is proposed, based on the published literature and the findings of the current investigation.