Synthesis of new photoactive urethane carbohydrates and their behavior in UV or femtosecond laser-induced two-photon polymerization

Abstract

Three methacrylated glycomonomers (CMA-1-3) were synthesized, characterized, and photocrosslinked in hydrophilic conetworks. The UV photobehavior of monomers was evaluated through FTIR spectrometry using Irgacure 819/Irgacure 2959 as photoinitiator, and the results showed that Irgacure 2959 is a better photoinitiator, the conversion degree (DC) varying in the range of 69-89.2% and the maximum rate of polymerization (Rmaxp ) being ~10 s-1. The addition of poly(ethylene glycol) dimethacrylate (PEG-DMA) or benzophenone macromer (BP-UDMA) as co-monomer improved the Rmaxp and DC (up to 100% after 300 s of irradiation in the latter). Specific analysis (gel fraction, water uptake, morphology) of the photopolymerized networks A1-A3 (CMA-1-3/PEG-DMA) and B1-B3 (CMA-1-3/BP-UDMA) demonstrated that B1-B3 films have interconnected inner pores, with irregular shapes and different sizes. The grid structures created through the two-photon polymerization of B1-B3 formulations in the presence of Irg819 are clearer and have a controlled porosity, of relevance for promising bioapplications.