To identify the chemical modifications along nuclear tracks in poly(allyl diglycol carbonate) (PADC), we have made a series of Fourier transform infrared (FT-IR) measurements for films with a thickness of about 3 µm that have been exposed to C, Ne, Ar, and Fe ions in air. The amount of carbonated ester bonds lost due to the exposure was estimated from the changes in the absorbance of C=O and C–O–C bonds with the heavy ion fluence. The G-value for the breaking of carbonate ester bonds and the corresponding track core radii were obtained as a function of stopping power. The calculated radial dose distribution indicated that the core was formed at regions where the local dose was higher than 106 Gy.