Electrospinning of Nylon-66 Polymer Nanofabrics

Abstract

This paper systematically studies the electrospinning and characteristics of Nylon-66 polymer nanofiber fabrics that were electrospun at two different collector drum speeds of 1.5 m/s and 3.0 m/s. It also evaluates the potential for producing nanofiber fabrics with uniform thickness using single-nozzle and multiple-nozzle electrospinning set-ups. The polymer concentration was varied from 6 – 12% by weight. The influence of collector drum speeds, electrospinning set-ups (single and multiple-nozzle) and polymer concentrations on the morphology, uniformity and mechanical properties of the electrospun nanofiber fabrics is studied in this paper. The nanofiber fabrics electrospun using multiple-nozzle electrospinning set-ups were observed to have more uniform thickness along their width than that electrospun using single-nozzle electrospinning set-up. The morphology characterization of the nanofiber fabrics showed formation of wet polymer (at 6% wt.), beads (at 8% wt.) at lower concentrations of polymer and dry fibers without beads at higher concentration (at 10 and 12% wt.). It was observed that the diameter of the fibers increased as the polymer concentration increased and it decreased as the collector drum speed increased. The diameter of the fibers were in the range of 20-100 nm for 6% Nylon-66 fabric and 120 – 240 nm for 12% Nylon-66 fabric. The mechanical characterization involved the measurement of tensile modulus and strength in the longitudinal (collector drum rotating direction) and transverse directions. The fabrics electrospun at 1.5 m/s had almost same properties in both the directions while the fabrics electrospun at 3.0 m/s had higher properties in the longitudinal direction. This showed that at collector drum speed of 1.5 m/s the nanofibers in the fabrics were randomly oriented and as the speed increased to 3.0 m/s they became directionally oriented (or partially aligned) towards the drum rotating direction. Finally, the mechanical properties of the fabrics measured in the present work are compared with that of literature data and commercial Nylon-66. It was observed that the present results are better than the literature data and comparable to some of the properties of commercial bulk Nylon-66.