Patcharaporn Thitiwongsawet, Prapaporn Sae-Lee, Preeya Kwanduen, Watchanida Chinpa, and Pitt Supaphol

pp. 315 - 323

Abstract

Poly(bisphenol A-co-4-nitrophthalic anhydride-co-1,3-phenylenediamine) (PEI) fibers were successfully prepared by
electrospinning from PEI solutions in dichloromethane (DCM), 1,2-dichloroethane (DCE), N-methylpyrrolidone (NMP) and
certain mixtures between NMP and N,N-dimethylformamide (DMF). Electrospinnability of PEI solutions in NMP was greater
than that in DCM and DCE. The addition of DMF with NMP for the preparation of PEI solutions helped improve electrospinnability of the PEI solutions. The effect of solution concentration on morphological appearance and/or size of the obtained
products was investigated. At low concentrations of the PEI solutions, discrete beads and/or beaded fibers was formed.
Smooth fibers were obtained at the highest concentration investigated, i.e., 20% (w/v). The size of the obtained fibers was
found to be an increasing function with the solution concentration or, to be exact, the solution viscosity. The water fluxes
through the electrospun fiber mats prepared from 20% (w/v) PEI solutions in 75/25 and 50/50 NMP/DMF mixtures were
investigated in comparison with the films prepared by phase immersion-precipitation technique. The fiber mats exhibited
much greater fluxes of water than the films, which implied their potential for uses as filtration membranes.