High Performance Electrospun Polynaphthalimide Nanofibrous Membranes with Excellent Resistance to Chemically Harsh Conditions

Polynaphthalimide (PNI) with six-membered imide ring (6-PI) has better chemical resistance than five-membered imide ring (5-PI), but is difficult to be processed into nanofibers due the poor processability. In this work, we proposed a template strategy to fabricate nanofiber 6-PI membranes and their composite membranes. Pure 6-PI and 6-PI composite fibrous membranes were prepared using high-molecular-weight polymers 5-PAA and PVP as templates by electrospinning. FT-IR, DMA, TGA and tensile tests were used to characterize their chemical structures, thermal stability and mechanical properties. Further eye-observation, micro-morphology investigation and tensile tests were applied to evaluate the chemical resistance of nanofibrous membranes in strong acid, strong alkaline, and concentrated salt. The results demonstrated that 6-PI nanofibrous membranes possessed the best thermal stability, best acid, alkaline, and salt resistance with the highest mechanical retention. This research will provide basic information for high-performance electrospun 6-PI nanofiber membranes and provide opportunities for applications of PIs in different chemically harsh environments.