DIFFUSION OF GOLD AND SILVER IN BISPHENOL A POLYCARBONATE

Diffusion of evaporated gold arid silver into Bisphenol A polycarbonat e has been studied using the radiotracer technique in combination with ion beam sputtering for serial sectioning. Diffusion coefficients bet ween 4 x 10(-14) and 1 x 10(-16) cm(2) s(-1) were measured in the temp erature range between 210 and 130 degrees C. The metal concentration i n the polymer turned out to depend strongly on the evaporation rate. A n Arrhenius-like temperature dependence with activation energies of 1. 02 eV for silver and 1.13 eV for gold was found. The low diffusivities , which are not affected by the polymer dynamics, are interpreted with in molecular theories for diffusion of gases in polymers with an addit ional attractive interaction between metal atoms and polymer chains.