MD simulations of ion–organic styrene‐containing polymer interactions are reviewed and compared to experiment. We report results for argon ion bombardment of PS, PαMS and P4MS. All three polymers exhibit the formation of a similar, highly cross‐linking, dehydrogenated near‐surface damaged layer at steady state, but small changes in the structure of the polymer (P4MS and PαMS are isomers) can lead to drastic changes in the initial transient sputtering of the material. We correlate this behavior to differences in radiation chemistry (P4MS and PS are cross‐linking while PaMS is a chain scission polymer), and examine how the behavior in MD may relate to larger‐scale experimental results, such as roughness formation.