p-Styrenesulfonate derivatives having cycloaliphatic epoxide in a molecule, were synthesized. Oligomerization of the monomers and co-polymerization of the novel monomers with tert-butyl methacrylate were carried out. When the polymer films containing a photoacid generator (PAG) were irradiated, they became insoluble in solvents. The insoluble films became soluble in water on baking at 120-200 degreesC. The insolubilization and redissolution profiles were strongly affected by the structure of the monomer, irradiation and baking conditions, and a type of PAG used. The reaction mechanism was studied by TGA analysis and FT-IR spectroscopy. (C) 2004 Elsevier Ltd. All rights reserved.