The influence of inorganic materials on the pyrolysis of polytetrafluoroethylene. Part 2: The common oxides of Al, Ga, In, Zn, Cu, Ni, Co, Fe, Mn, Cr, V, Zr and La

• PTFE was pyrolysed in the presence of aluminium- and fourth period metal oxides.
• Al2O3 was shown to increase the yield of hexafluoropropylene.
• CuO was shown to produce CO2 and short chain perfluoroalkanes in addition to tetrafluoroethylene.
• V2O5 reacted in bulk with PTFE to produce mostly CO2 and TFE.
• The other metal fluorides were shown to be generally inactive as catalysts.

The thermal decomposition of PTFE intimately mixed with the common oxides of selected metals (Al2O3, Ga2O3, In2O3, ZnO, CuO, NiO, Co3O4, Fe2O3, Mn2O3, Cr2O3, V2O5, ZrO2 and La2O3) was investigated by TGA-FTIR. Except for ZrO2, all the oxides undergo reaction with PTFE to produce some CO2. CuO and V2O5 react in bulk and speed up the degradation rate with V2O3 also lowering the mass-loss onset temperature by 60 °C. Al2O3 moderately increases the yield of hexafluoropropylene and hexafluoroethane.

The catalytic pyrolysis of PTFE was investigated using Al2O3, CuO and other oxides of selected fourth period transition metals. Product shifts favouring hexafluoropropylene formation were observed with Al2O3. CuO filled PTFE pyrolysed to produce CO2, TFE and short chain fluorocarbons. Most other oxides were inert to PTFE.Figure optionsDownload as PowerPoint slide