Morphology and Thermal Stability of Electrospun Nanofibers Based on Polymer Nanocomposite With Methylimidazolium Ionic Liquid

Abstract

New composite materials were prepared by electrospinning/casting method aiming the preparation of membranes for fuel cell application. Non-woven nanofiber mats of poly(styrene sulfonic acid-co-maleic anhydride) (PSSAMA)/poly(vinyl alcohol) (PVA)/Ionic liquid (IL) blends were prepared by electrospinning using water as solvent. The mass ratio PSSAMA/PVA = 2/3 was employed and 1-Butyl-3-methylimidazolium trifluoromethanesulfonate (BMIM TfO) was used as IL, in the content of 10, 30, and 50 wt% concerning the polymers. Scanning electron microscopy (SEM) showed that these materials are dense structures formed by nanofibers which can act as composite filler and proton conducting elements. SEM micrographs revealed also that the addition of the smaller amount of BMIM TfO to the blend decreases the average diameter of the fiber up to 76 nm when compared with fibers prepared without any IL (average diameter = 123 nm), and the global effect of this addition of IL is the reduction of the average diameter of the fibers of the PSSAMA/PVA mixture. Thermogravimetric analyses (TGA) showed that nanofibers on set degradation temperature was not altered up to 30 wt% of IL (295 °C), but it decreases to 260 °C when 50 wt% of BMIM TfO was added to the fiber.