Effect of Thermal Treatment on Crystallinity of Poly(ethylene oxide) Electrospun Fibers

Abstract

Post-process thermal treatment of electrospun fibers obtained from poly(ethylene oxide) (PEO) water and methanol solutions was examined. PEO fibers from methanol solution showed larger diameters as observed by scanning electron microscopy. Fibers both from water and methanol solutions exhibited a significant dimensional stability and surface cracking during the specific exposure time after thermal treatments at 40, 50, and 60 °C. Changes in crystallinity after the thermal treatment were studied by wide-angle X-ray diffraction. The kinetics of secondary crystallization were positively influenced by the as-processed level of the amorphous phase and temperature of thermal treatment. Samples treated at 60 °C were degraded by thermooxidation within the time.

Processing of (Co)Poly(2-oxazoline)s by Electrospinning and Extrusion from Melt and the Postprocessing Properties of the (Co)Polymers

“…Such results may be attributed to the orientation of the macromolecular chains within the polymer in the longitudinal fibre direction under an electrostatic field during the electrospinning process, which may promote crystallisation. Such effect was also observed for other polymers [54][55][56][57]. Similarly, P(iPrOx-nPrOx) copolymers were amorphous before electrospinning, but a nonsymmetric peak (∆H~2.7 J/g) was visible in the DSC trace after its processing, indicating crystallisation.…”

Melt-Electrospun Polyethylene Nanofiber Obtained from Polyethylene/Polyvinyl Butyral Blend Film

“…The ethanol treatment was applied to as-spun LDPE/PVB blend fibers at room temperature for 6 h. To remove PVB from closely associated LDPE, ethanol enters the core of the LDPE fiber and enhances the arrangement of polymer chains after the PVB matrix dissolves. Polaskova et al [43] also observed the improved molecular orientation and crystallinity of electrospun fiber with accompany of methanol solution. Like LDPE/PVB film, the crystallinity of PVB-removed LDPE fiber was improved by the increase of PVB content in blend fibers.…”

“…The crystallinity of LDPE was drastically decreased for electrospinning in blends with higher PVB content. Generally, the crystallinity of a polymer is a function of the supercooling [41,42] and is significantly lower for electrospun fibers compared to samples prepared by common processing technologies (molding or film casting) [43]. Here, M-ESP was conducted at room temperature, where the polymer was melted at around 200 °C by laser, and as-spun fibers were collected immediately by a collector.…”

A mini review on the generation of crimped ultrathin fibers via electrospinning: Materials, strategies, and applications

“…It is worth mentioning that the surface morphology and properties of electrospun fibers can be affected by (I) the working parameters of the electrospinning process represented by ambient parameters (relative humidity and temperature), solution parameters (polymer concentration, molecular weight, viscosity, conductivity, and surface tension), and processing parameters (flow rate, applied voltage, distance between the tip of the needle and the collector [DTC], collector type, and diameter of the needle); (II) electrospinning types; (III) composites; and (IV) postprocessing treatments …”