Melt Electrospinning Polyethylene Fibers in Inert Atmosphere

Abstract

Electrospinning is commonly used for fabrication of polymer fibers. Melt electrospinning, instead of the commonly used solution electrospinning, offers many advantages in generating polymer fibers without using solvents. However, polymer melts have high viscosity which poses major limitations in producing low diameter fibers. Here, melt electrospinning is investigated at elevated temperatures in inert atmosphere to reduce fiber diameters while suppressing thermal degradation. Two types of spinneret configurations, syringe and wire, with two distinct outcomes are studied. In syringe‐based electrospinning, increasing the nozzle temperature from 300 to 360 °C in nitrogen reduced fiber diameter significantly from 33 ± 5 to 10 ± 4 µm. Electrospinning in nitrogen leads to formation of fibers even at a high nozzle temperature of 360 °C, while this temperature leads to thermal degradation when spinning in air. In contrast, increasing the temperature of wire electrospinning setup do not lead to a noticeable reduction in diameter. This is attributed to the viscosity‐dependent flow rate in this method. Increasing the temperature leads to increased flow rates, promoting the formation of thicker fibers, while the increased stretchability promotes the formation of thinner fibers. The results clearly demonstrate advantages of developing polymer microfibers in inert atmosphere to avoid thermal degradation with a temperature‐independent flow control.

Effect of the spin‐line temperature profile on the mechanical properties of melt electrospun polyethylene fibers

“…Precise control of the temperature in the spinning zone enabled us to fabricate fibers with only ~10 microns on average without the need for increasing the melting temperature. Obtaining such a low diameter range is extremely challenging for PE in the melt electrospinning process due to high viscosity nature and complex processability 28 . Systematic advancements in mechanisms of fiber diameter reduction in melt electrospinning, being one of the major bottlenecks for its industrial applications, merits systematic process‐structure‐properties correlation development carried out throughout this work.…”

“…Polyethylene (PE) was first melt‐electrospun by Larrondo et al 26 and several other researchers have used low‐density PE for melt electrospinning so far. The PE fibers produced have fiber diameters ranging from few microns to several hundreds of microns 27,28,26 . In application, the mechanical integrity of the electrospun material ultimately determines whether it will hold up under end‐use conditions.…”

Multiphysics modeling and experimental verification of solidification point of melt-electrospun jet

“…Increasing the spinneret temperature is an effective way to reduce the fluid viscosity. [16][17][18] This technique will provide another idea for jet thinning: on the one hand, increasing the initial liquefy temperature from the melting temperature to the cracking temperature reduces the viscosity; on the other hand, decreasing the convective heat transfer gradient to realize the jet solidification delay by means of increasing the temperature of surrounding medium. The influence of the heating temperature of the spinneret on the fiber properties, studied by the Mu team, 19 is worthy of reference.…”