Novel thermally latent self-crosslinkable copolymers (14 and 15) containing hemiacetal ester and oxetane moieties were synthesized by the radical copolymerizations of 1-propoxyethyl methacrylate, 3-ethyl-3-methacryloyloxymethyl oxetane, and/or n-butyl methacrylate at 60 degrees C in the presence of 2,2-azoisobutylonitrile as an initiator. The obtained copolymers showed good solubility for common organic solvents such as tetrahydrofuran, chloroform, and dimethyl sulfoxide (DMSO). The thermal crosslinking behaviors were examined with several Lewis acid catalysts (6). In particular, the treatment with aluminum-2-ethylhexanate triethanolamine complex (6c) at 160 degrees C was found to efficiently yield the corresponding self-crosslinked polymers (14' and 15'). Incidentally, the resulting products were hardly insoluble in various organic solvents, including DMSO. The thermal properties of the obtained self-crosslinked polymers 14' and 15' were estimated by thermogravimetric analysis and differential scanning calorimetry. (c) 2005 Wiley Periodicals, Inc.