Chemically Versatile Aromatic Polyimides from Water-Borne Poly(amic Acid) Salts Synthesized by Surfactant-Assisted Aqueous Polymerization

The water-borne aromatic poly(amic acid) salt (W-PAASs) is gaining attention as an eco-friendly approach to synthesizing precursors for high-performance polyimide (PI) materials. However, widening the versatility of the chemical structure in aromatic monomers for tuning the novel physical properties of the resulting polymers remains challenging. In this study, we introduce a surfactant-assisted, one-pot synthesis of W-PAASs, an efficient approach to broadening the chemical diversity of water-borne PI precursors. The surfactant effectively increases the interface of hydrophobic monomers with the aqueous medium, accelerating the reaction between the dianhydride and diamine monomers. This enables the use of hydrophobic monomers such as 4,4-oxidianline, 1,3-bis(4-aminophenoxy)-benzene, and 4,4-diaminophenyl sulfide. The chemical versatility of synthetic monomers allows for the preparation of PI films with novel mechanical, thermal, and optical properties. Our findings demonstrate that improving the synthetic environment for W-PAAS is crucial for developing advanced engineering plastics through sustainable, eco-friendly processes, paving the route for future high-tech applications.