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 Pb 2 F 2 O and PbF 2 . 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.