Thermochemical Reaction of Lead Oxide with a Polytetrafluoroethylene Matrix

Thermochemical transformations that lead oxide used as filler in a polytetrafluoroethylene matrix undergoes in the course of heat treatment were studied. Samples were prepared from a mixture of the polymer with the filler by pressing followed by heat treatment. X-ray diffraction analysis shows that the heat treatment in air leads to multistep thermochemical reaction of the polymer with the inorganic filler with the formation of Pb2F2O and PbF2. Presumably, dispersed lead oxide particles occurring in intimate contact with the polymer, when heated in air, initiate the polymer degradation via cleavage of the C−F bond to form new compounds. Along with the formation of new compounds, the reduction of lead oxide to the metal is observed.