TWO-STEP CROSSLINKING OF PVP/GEL NANOFIBERS

In this study, it was achieved that crosslinking of PVP/GEL nanofibers with two-steps. Crosslinking is a process highly important for water-soluble polymers in terms of application areas and mechanical properties. Firstly, crosslinking of PVP polymers experimental studies were carried out via heat treatment at different temperatures and times. Then, GEL polymers were crosslinked with GTA vapour at different times. Morphological analysis was carried out via SEM images and chemical characteristics were determined via FT-IR analysis. Moreover, after the crosslinking process, SD and WL values were calculated. All results showed that before crosslinking of SEM images, nanofibers were smooth, fine and without beads. The average fiber diameter is 196 nm and the fiber diameter distribution is quite uniform. After crosslinking of SEM images, it is expected that all nanowebs will turn from fibrous surfaces to membranous. Generally, SD and WL values decrease with crosslinking time increase. According to all of the SEM images, SD and WL values, optimum conditions were determined for PVP as 4 hours at 180oC and for GEL as 24 hours. Lastly, the presence of PVP and GEL polymers in the nanofiber structure was verified chemically with FT-IR analysis.