Thiol-ene modification of electrospun polybutadiene fibers crosslinked by UV irradiation

Electrospun polybutadiene (BR) was crosslinked in situ during the spinning process to obtain stable fibers. Crosslinking was induced by addition of photoinitiator to the electrospun BR solution. Due to the very low glass transition temperature (Tg) of BR (below −80 °C) it is necessary to crosslink the fibers thereby improving the mechanical properties and creating stable fibers by preventing fibers from melting together. In order to prevent the polymer fibers from melting onto the grounded collector, a solution of sodium chloride in methanol was used to collect the fibers thereby letting the fibers float and increase the irradiation time of the UV curing during the electrospinning process. Subsequent surface modification via thiol-ene click chemistry on remaining CC bonds was successfully employed with mercaptoethanol or thioglycolic acid, leading to superhydrophilic fiber mats.