Synthesis and Photostructuring of Hybrid Photopolymers with Cinnamate and Anil Moieties by using UV Light and Femtosecond Laser Pulses

Two photosensitive methacrylates containing urea and two cinnamates (N,N–di(cinnamoyloxyethyl) N'-methacryloyloxyethyl urea, DC-MA), or urethane and saliciliden-aniline (anil) groups (methacryloyloxyethyl-2-carbamoyloxy(m-methyl, o-hydroxybenziliden)-aniline, UAn-MA) were synthesized and used besides N,N'-(methacryloxyethyldietoxy-methylsilylpropyl)-urea (UH-MA) in the preparation and photostructuring of hybrid photopolymers. Polymerization of the monomers was investigated by differential scanning photo calorimetry (photo-DSC), Fourier transform infrared (FTIR) and near-infrared (NIR) spectroscopies. The rate of photopolymerization increased upon adding UH-MA in formulation (DC-MA/UH-MA, Rp = 9.1 × 10−2 s−1; UAn-MA/UH-MA, Rp = 2.32 × 10−2 s−1), the degree of conversion being between 33 and 76%. Scanning electron microscopy (SEM), atomic force microscopy (AFM), and optical microscopy confirmed the formation of bidimensional hybrid microstructures by using two-photon polymerization (2PP).