A new class of high-performance thermoset resins using dicyanoimidazole (DCI) as crosslinking group: A key demo of synthesis, curing behavior and thermal properties

Abstract A novel full-aromatic dicyanoimidazole (DCI) resin monomer—2,2'-((1,4-phenylenebis(oxy))bis(4,1-phenylene))bis(1H-imidazole-4,5-dicarbonitrile) (4PODCI)was synthesized by a simple Schiff base route. A variety of research methods (including FT-IR, UV–Vis, molecular simulation, model monomer, etc.) were applied to study the curing behavior of 4PODCI, the results show that the curing reaction of 4PODCI can be accelerated by N–H on the imidazole, and triazine is observed in the cured products. The 5% weight loss (T5%) of cured 4PODCI under nitrogen and air atmosphere is as high as 591 °C and 558.5 °C respectively, and its Tg is above 500 °C. These results confirm the excellent thermal and thermomechanical properties of cured 4PODCI, and DCI can be employed as a new type of cross-linked elements of high-performance thermosetting resin.