Chlorofluorocarbon-22 (HCCIF2) gas call react with acetonitrile to form a halogen-free carbon-based polymer when solid potassium hydroxide particles are present. The reaction can be carried out under nor mal pressure and at room temperature. The polymer is powdery and amorphous. The structure of the polymer has been studied by elemental analysis, Fourier transform Iii, Raman, and mass spectroscopies. The results demonstrate that the polymer has a carbonic backbone.