Green synthesis of polyureas from CO2 and diamines with a functional ionic liquid as the catalyst

摘要

A series of ionic liquids (P4,4,4,6BF4, P(4,4,4,6)Triz, as well as the newly prepared anion dual-functionalized amino-triz IL P(4,4,4,6)ATriz, etc.) were prepared, and their catalytic performance was tested in the synthesis of polyureas from CO2 and diamines. Under the optimized reaction conditions, good to excellent yields of various polyureas were achieved with different diamines over P(4,4,4,6)ATriz catalyst. It can be found that the catalytic performance is essentially consistent with the basicity of ILs (as determined by TPD method). The solid products were characterized extensively by C-13 NMR, FT-IR, XRD, DSC and TGA. From these results, it could be concluded that the solid products based on diamines and CO2 have the polyurea structure with the urea linkage and connected by hydrogen bonds, which resulted in their high resistance to solvents and excellent thermal stability.