Effect of the Fiber Diameter of Polyamide 11 Nanofibers on Their Internal Molecular Orientation and Properties.

Herein, the effect of the diameter of polyamide 11 nanofibers (PA11 NFs) on their internal structures as well as thermal and mechanical properties is investigated. Aligned PA11 NFs with diameters ranging from 109 to 462 nm are prepared by the single-component solvent electrospinning of different PA11/1,1,1,3,3,3-hexafluoro-2-propanol (HFIP) solutions (4-8 wt%) and subsequently characterized. Owing to the similar hydrogen bond formation within the NFs during electrospinning, all prepared NFs have δ'-phase crystals with similar crystallinities and crystallite sizes.

Verification of the Influence of Processing History through Comparing High-Speed Melt Spinning Behavior of Virgin and Recycled Polypropylene.

A 'model' material of recycled polypropylene (PP) was prepared through the injection molding process, and the effect of processing history on the polymer characteristics was investigated through the high-speed melt spinning of virgin and recycled PP. On-line measurement of the thinning behavior of the spin-line revealed the downstream shift of solidification point for the recycled PP at the take-up velocity of 1.0 km/min, indicating the suppression of flow-induced crystallization.

Laser-Assisted Melt Electrospinning of Poly(L-lactide-co-ε-caprolactone): Analyses on Processing Behavior and Characteristics of Prepared Fibers.

The laser-assisted melt electrospinning (LES) method was utilized for the preparation of poly(L-lactide-co-ε-caprolactone) (PLCL) fibers. During the process, a carbon dioxide laser was irradiated, and voltage was applied to the raw fiber of PLCL. In situ observation of fiber formation behavior revealed that only a single jet was formed from the swelling region under the conditions of low laser power and applied voltage and feeding rate, whereas multiple jets and shots were produced with increases in these parameters.

Planar or Biaxial Stretching of Poly(ethylene terephthalate) Fiber Webs Prepared by Laser-Electrospinning.

In this work, laser-heated electrospinning (LES) process using carbon dioxide laser was explored as an eco-friendly method for producing ultrafine fibers. To enhance the thinning of fibers and the formation of fiber structure, planar or equibiaxial stretching and subsequent annealing processes were applied to poly(ethylene terephthalate) (PET) fiber webs prepared by LES. The structure and properties of the obtained webs were investigated.

Bamboo Charcoal/Poly(L-lactide) Fiber Webs Prepared Using Laser-Heated Melt Electrospinning.

Although several studies have reported that the addition of bamboo charcoal (BC) to polylactide (PLA) enhances the properties of PLA, to date, no study has been reported on the fabrication of ultrafine BC/poly(L-lactide) (PLLA) webs via electrospinning. Therefore, ultrafine fiber webs of PLLA and BC/PLLA were prepared using PLLA and BC/PLLA raw fibers via a novel laser electrospinning method. Ultrafine PLLA and BC/PLLA fibers with average diameters of approximately 1 μm and coefficients of variation of 13-23 and 20-46% were obtained.

Preparation of Perfluorosulfonated Ionomer Nanofibers by Solution Blow Spinning.

In this work, we report the preparation of high-purity perfluorosulfonated ionomer (Nafion) nanofibers (NFs) via solution blow spinning (SBS). Fiber formation in solution jet spinning is strongly dependent on the structure of the spinning solution. Upon adding a small amount of poly(ethyleneoxide) (PEO) as a spinning aid to Nafion dispersion, most of the highly ordered Nafion aggregate disappeared, allowing the stable production of bead-free and smooth high-purity NFs (Nafion/PEO = 99/1) by SBS.

Melt-Spun Fibers from Bio-Based Polyester-Fiber Structure Development in High-Speed Melt Spinning of Poly(ethylene 2,5-furandicarboxylate) (PEF).

Poly(ethylene 2,5-furandicarboxylate) (PEF) is regarded as a bio-based alternative or complementary polyester for the widely used fossil resource-based polyester, poly(ethylene terephthalate) (PET). High-speed melt spinning of PEF of low and high molecular weight (L-PEF, H-PEF) was conducted, and the structure and properties of the resultant as-spun fibers were investigated. The occurrence of orientation-induced crystallization was confirmed for the H-PEF at the take-up velocity of 6.

Structure and Properties of Poly(ethylene terephthalate) Fiber Webs Prepared via Laser-Electrospinning and Subsequent Annealing Processes.

Melt-electrospinning is an eco-friendly method for producing ultra-fine fibers without using any solvent. We prepared webs of poly(ethylene terephthalate) (PET) through melt-electrospinning using CO laser irradiation for heating. The PET webs comprised ultra-fine fibers of uniform diameter (average fiber diameter = 1.