The vapor induced modification of bulk samples of syndiotactic random copolymers of styrene and p-n-butylstyrene is studied by wide-angle X-ray scattering and light microscopy. Two samples with p-n-butylstyrene contents of 4 and 11 mol% are compared. It is shown that treatment with CHCl3 leads to the formation of a clathrate modification similar to that of neat syndiotactic polystyrene. The change of the surface topography of the copolymers as a result of CHCl3 vapor exposition is studied by tapping-mode/height-mode atomic force microscopy.