Crosslinked electrospun polybutadiene (BR) fibers were made using electrospinning and UV curing methods. The crosslinked BR fibers were obtained by irradiating UV light on the electrospun BR fibers containing a photoinitiator and a crosslinker. Although uncrosslinked electrospun BR fibers did not retain the fiber morphology at room temperature due to a cold flow resulting from the very low glass transition temperature (T-g) of BR (below -80 degrees C), the crosslinked electrospun BR fibers retained the fiber mor-phology. The crosslink density increased with increase of the content of crosslinking agent. The crosslinked BR fibers had higher T-g than the raw BR. Tensile strength, modulus, and elongation at break of the electrospun BR fiber mats increased with increase of the crosslinker content. (c) 2006 Wiley Periodicals, Inc.