New polyacrylates with photosensitive triazene groups designed for laser ablation: Synthesis, structure and properties

Two new triazene monomers, such as (1-(para methoxy-phenyl)-3-(2 acryloyloxyethyl)-3-methyl triazene-1, M1) and (1-(para chloro-phenyl)-3-(2 acryloyloxyethyl)-3-methyl triazene-1, M2) were synthesized and further employed as reaction partners with methyl methacrylate (MMA) in order to investigate the substituent effect of the triazene moiety on the polymeric properties. The synthesized monomers and polymers (PA1, molar fraction of M1 = 0.16; PA2, molar fraction of M2 = 0.11) were characterized by analytical and spectroscopic methods, while the surface morphology of polymers was visualized by atomic force microscopy (AFM) and optical microscopy. The photosensitivity of these copolymers was evaluated upon UV exposure, in solution and in film state, following the decreasing value of the π–π* absorption band corresponding to the triazene group centered at 290 nm and 320 nm. For both copolymers, the kinetic data indicated a first-order photoprocess, as evidenced from the determined constant rate in film state (PA1, k = 2.3 × 10−3 s−1; PA2, k = 2.7 × 10−4 s−1). Moreover, the ablation characteristics achieved at low fluence for an irradiation wavelength of 308 nm, quality structuring with no any debris and the absence of carbonization of the irradiated areas suggest that such photolabile polyacrylates could offer new possibilities in printing techniques and nanostructures on surfaces. In addition, the triazene functions introduced as side groups may be used for the tailoring of special polymeric architectures.