3D-VAT printing of nanocomposites by photopolymerisation processes using amino-meta-terphenyls as visible light-absorbing photoinitiators

In this article, the application of 10 new amino-m-terphenyls in 3D-VAT printing was described. New compounds have specially designed D-π-A structure, where the central phenyl ring with nitrile and amino groups is the acceptor and the modifiable amino group is donor. Such design eliminates problem with acid scavenging and guaranteed desire properties and photoactivity as well as it allows further development of such system for 3D-VAT printing. Efficient excitation with intramolecular charge transfer provides excellent absorption and electrochemical properties, which can be tuned by modification of the amino group. The design allows photoinitiation of free radical, hybrid and especially cationic polymerisation even at 455 nm with more than 70% of monomer conversion. Such properties allow to use the developed compounds as efficient visible light photoinitiators for 3D printing of nanocomposite materials. The terphenyls can efficiently cure resins containing CuO and Al2O3 nano additives leading to high-resolution 3D prints.