1-(Phenyl)-3-(2-acryloyloxyethyl)-3-methyl triazene-1 (M1) and 1-(p-nitrophenyl)-3-(2-acryloyloxyethyl)-3-methyl triazene-1 (M2) were synthesized to study the substituent effect of the triazene unit on the copolymerization with methyl methacrylate (MMA). From the H-1 NMR spectra of the resulting copolymers, their compositions were determined to be 1:3.18 M1/MMA and 1:2.45 M2/MMA, respectively. The polymers were examined with respect to their structure, thermal properties, and surface morphology. The influence of the triazene structure on the photosensitive properties of the copolymers exposed to ultraviolet/laser irradiation was also investigated and compared with that of the parent derivatives. The copolymer containing the phenyl triazene chromophore as the photochemically most active group exhibited a low threshold of ablation and a high etching rate for fluences under 400 mJ cm(-2). Scanning electron microscopy images confirm the formation of ablated craters more clearly in the copolymer made with M1, for which the thermal effects of the ablation mechanism were visible only with 2500x magnification. (c) 2006 Wiley Periodicals, Inc.