The Roles Played by DMF in the Structure Formation of Epoxy-Based Porous Monolith

Epoxy-based porous monoliths are prepared by chemically induced phase separation. The roles played by N,N-dimethylformamide (DMF) in both curing and phase separation kinetics are studied in detail. It is found that the addition of DMF not only changes the speed of phase separation, but the way. Meanwhile, the occurrence of secondary phase separation is partly inhibited, which is in favor of the formation of skeletal network structure. In addition, the schematic pseudo phase diagrams were deduced, which are of great significance to understand the roles played by DMF for the targeted control of materials structure. The results show that by the addition of DMF, the phase diagram moves to the lower right, which means more porogen is needed to obtain skeletal network structure. The spinodal line moves toward the binodal line and the internal space of spinodal line is enlarged. Therefore, it becomes more available to obtain skeletal network structure.