One-pot one-step synthesis of a photo-cleavable cross-linker via Passerini reaction for fabrication of responsive polymeric particles

A new approach for the synthesis of a photo-cleavable cross-linker and preparation of light-responsive polymeric particles is proposed in the current work. A multicomponent reaction, Passerini reaction, is employed as a one-pot one-step synthetic approach for the preparation of the acrylate-based cross-linker (hexane-1,6-diylbis(azanediyl))bis(1-(2-nitrophenyl)-2-oxoethane-2,1-diyl) diacrylate) (PCDA). Briefly, Passerini reaction of 1,6-diisocyanohexane, 2-nitrobenzaldehyde and acrylic acid yields the photo-cleavable diacrylate with o-nitrobenzyl ester moieties. Subsequently, the cross-linker is successfully utilized in the preparation of poly(methyl methacrylate) microspheres and nanospheres via suspension and miniemulsion polymerization, respectively. Finally, light-induced degradations of the polymeric particles are conducted under UV light illumination (around 366 nm). All compounds and products in each step are well characterized by FTIR, ¹ H-NMR, UV–Vis spectroscopy, light microscopy and SEM.