The influence of inorganic materials on the pyrolysis of polytetrafluoroethylene. Part 1 : the sulfates and fluorides of Al, Zn, Cu, Ni, Co, Fe and Mn

Abstract

The thermal decomposition of PTFE intimately mixed with the solid sulfates and fluorides of selected metals (Al2(SO4)3, ZnSO4, CuSO4, NiSO4, CoSO4, FeSO4, AlF3, CuF2, NiF2, CoF2, FeF2 and MnF2) was investigated by TGA-FTIR. It was found that the sulfates affect the rate of pyrolysis with CuSO4 lowering mass-loss onset temperature by 60 °C. The fluorides have no effect on the pyrolysis rate, with the exception of AlF3 which lowers the onset temperature by 35 °C. It was also found that Al2(SO4)3 and NiSO4 moderately increase the yield of hexafluoropropylene, and that AlF3 shifts the product composition to almost exclusively hexafluoropropylene and hexafluoroethane.