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.本文介绍了10种新型氨基间三联苯（amino-m-terphenyls）在3D-VAT打印中的应用。这类化合物具备精心设计的给体-π-受体（D-π-A）结构：其中带有氰基与氨基的中心苯环充当受体单元，可修饰的氨基则作为给体单元。该设计规避了酸清除的难题，同时保障了理想的性能与光活性，亦为该体系面向3D-VAT打印的后续开发提供了可行路径。借助分子内电荷转移实现的高效激发，赋予其优异的吸收性能与电化学特性，且可通过氨基修饰对上述性能进行精准调控。该设计可实现自由基聚合、混杂聚合乃至阳离子聚合的光引发，即便在455 nm波长下，单体转化率仍可超过70%。上述性能使得所开发的化合物可作为高效可见光光引发剂，用于纳米复合材料的3D打印。该类三联苯化合物可高效固化添加有氧化铜（CuO）与氧化铝（Al₂O₃）纳米添加剂的树脂，进而制备出高分辨率的3D打印件。