An Investigation on the Effect of Urea on the Electrospinnability of Polyvinyl Alcohol Solutions

ABSTRACT Polyvinyl alcohol (PVA) has been widely used in electrospinning due to its ease of processing and ability to aid in the electrospinning of challenging polymers. However, it is expensive. This study explores the use of urea, a highly water‐soluble, nitrogen‐rich (46%) compound, as a cost‐effective alternative to PVA in aqueous solutions. Electrospinning of PVA‐urea nanofibers containing up to 75% urea was successfully achieved, with electrical conductivity identified as a key factor in controlling fiber diameter. The diameter of the electrospun fibers ranged from 298 ± 42 nm to 345 ± 55 nm. FTIR analysis confirmed interactions between PVA and urea, indicating cross‐linking between PVA macromolecules. X‐ray diffraction (XRD) patterns revealed urea crystallization within the predominantly amorphous PVA matrix at low urea concentrations. Cross‐linking PVA‐urea nanofibers with glutaraldehyde reduced water solubility. The results also showed that the water solubility of PVA decreased by about 90% after cross‐linking with glutaraldehyde under acidic conditions. The release of urea from the nanofibers followed Fickian and Higuchi models, demonstrating controlled release properties. Given its low cost and availability, urea presents a viable substitute for PVA, particularly for applications where PVA is used to facilitate the electrospinning of otherwise difficult‐to‐process polymers.