Thresholds of Etchable Track Formation and Chemical Damage Parameters in Poly(ethylene terephthalate), Bisphenol A polycarbonate, and Poly(allyl diglycol carbonate) Films at the Stopping Powers Ranging from 10 to 12,000 keV/µm

Abstract

The damage structure of latent tracks in poly(ethylene terephthalate) (PET) has been examined by Fourier transform infrared (FT-IR) measurements. Results are compared with those from previous studies on bisphenol A polycarbonate (PC) and poly(allyl diglycol carbonate) (PADC). These polymers are exposed to protons and heavy ions (He, C, Ne, Si, Ar, Fe, Kr, and Xe) in air with energies less than 6 MeV/n, as well as gamma rays from an intense Co-60 source. Chemical damage parameters, namely, damage density, which is the number of losses of considered functional groups per unit length of tracks, radial size of the track core, in which the considered chemical groups are lost, and radiation chemical yields (G values) for each group are evaluated as a function of the stopping power. It has been confirmed that latent tracks will be etchable when the radial track core size is larger than the distance between two adjacent breaking points of polymer chains. The predominant breaking points are the C–O bonds in ether, ester, and carbonate ester bonds.