Photochemistry and Polymerization Efficiency of Bis-imidazole based Photoinitiator Systems

Rapid, continuous additive manufacturing by volumetric polymerization inhibition patterning

“…The concurrent photoinitiation and photoinhibition described here can be applied to a range of monomer classes for use in this AM system. HABIs exhibit several attributes favoring their potential as universal photoinhibitors of radical-mediated, chain-growth polymerizations, including their favorable absorbance spectra and the inability of HABI-derived lophyl radicals to directly initiate polymerization of (meth)acrylates ( 25 ), greatly expanding the compatible monomer palette. To demonstrate the broad applicability of our photoinitiator/photoinhibitor system, acrylate, methacrylate, and vinyl ether/maleimide (i.e., electron donor and electron acceptor monomers) resins (see Fig.…”

The Blue‐LED‐Sensitive Naphthoquinone‐Imidazolyl Derivatives as Type II Photoinitiators of Free Radical Photopolymerization

“…The unshared electron pair of the 1-position nitrogen atom in the imidazole ring participates to the conjugation, and the electron density of the nitrogen atom decreases, making the hydrogen on this nitrogen atom easy to leave as a hydrogen ion. [43,44] Hexaalkylbisimidazoles (HABIs) and their derivatives o-Cl-HABI and p-HOH-HABI were effective photoinitiators in thiol-alkene reactions. Under UV or short-wavelength visible light irradiation, HABI compounds can be interesting for thiol-alkene photopolymerization.…”