Electrospun zein fibers using glyoxal as the crosslinking reagent

After reaction of zein with glyoxal the resulting electrospun fibers have improved resistance to known zein solvents. Durable fibers with diameters of 0.6 mu m could be produced. The reaction between zein and glyoxal was carried out in acetic acid (AcOH) at temperatures between 25 and 60 degrees C at various lengths of time. Gelation would occur after higher extents of reaction. During the course of reaction, solution viscosity increased which increased the diameter of the electrospun fibers produced from these solutions. Gel electrophoresis showed increased molecular weight as the reaction progressed. When 6% glyoxal was allowed to react with zein at 25 degrees C for 6 h, the resulting fibers were durable to AcOH as spun. Other formulations required a second thermal treatment to provide solvent durable fabrics. Fibers displayed different secondary structure utilizing far-UV circular dichroism spectroscopy. The infrared spectra displayed peaks in the C-O region supporting the reaction of glyoxal with hydroxyl groups present on zein. Zein fabrics incorporating glyoxal had modestly improved tensile strength. (c) 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012