Nylon 66 nanofibers prepared by CO₂ laser supersonic drawing

Abstract

Nylon 66 nanofibers were prepared by irradiating as-spun nylon 66 fibers with radiation from a carbon dioxide (CO 2 ) laser while drawing them at supersonic velocities. A supersonic jet was generated by blowing air into a vacuum chamber through the fiber injection orifice. The fiber diameter depended on the drawing conditions used, such as laser power, chamber pressure, laser irradiation point, and fiber supply speed. A nanofiber obtained at a laser power of 20 W and a chamber pressure of 20 kPa had an average diameter of 0.337 lm and a draw ratio of 291,664, and the drawing speed in the CO 2 laser supersonic drawing was 486 m s 21 . The nanofibers showed two melting peaks at about 257 and 272 C. The lower melting peak is observed at the same temperature as that of the as-spun fiber, whereas the higher melting peak is about 15 C higher than the lower one. V C 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40015.

Broad poly(ethylene terephthalate) nanofiber sheet prepared by CO 2 laser supersonic continuous multi-drawing

“…T m2 was also observed in the DSC curve of PET and nylon 66 nanofibers as previously reported [14,16]. The nanofibers produced by CLSCMD thus exhibit T m2 , which is a unique feature.…”

“…CLSD has already been applied to prepare nanofibers of poly(Llactic acid) [1], poly(ethylene terephthalate) (PET) [11], poly(ethylene-2,6-naphthalate) [12], ethylene tetrafluoroethylene [13], nylon 66 [14], and poly(phenylene sulfide) [15]. The nanofibers obtained are infinitely long because large plastic deformation accompanied by stable necking occurs during CLSD.…”

Poly(l-lactic acid) nanofiber multifilament prepared by carbon dioxide laser supersonic multi-drawing

“…CLSD employs only CO 2 laser irradiation and does not require additional processes or solvents, unlike electrospinning, which requires a solvent, or sea-island-type conjugated melt spinning that requires the removal of a second component. CLSD has already been applied to prepare NFs of poly(L-lactic acid) (PLLA) [24], poly(ethylene terephthalate) (PET) [25], poly(ethylene-2,6-naphthalate) [26], poly(glycolic acid) (PGA) [27], ethylene tetrafluoroethylene copolymer [28], nylon 66 [29], and poly(phenylene sulfide) [30].…”

Nylon 66 Nanofiber Sheets Prepared by Carbon Dioxide Laser Supersonic Multi-drawing

“…In our research on the production of nylon 66 nanofibers by CLSD, we have reported that nylon 66 nanofibers were obtained that contained crystals having a melting temperature10-15 C higher than that ordinarily observed for nylon 66 15) . The quantity of such crystals having a higher melting temperature is related to the molecular orientation and an increase in the trans/gauche ratio.…”

“…The conditions for preparation nanofiber sheets by CLSMD were determined in reference to those for preparation single nylon 66 nanofibers using the CLSD system 15) . Table 2 compares the drawing conditions used for preparation nylon 66 nanofibers with the CLSMD and CLSD systems.…”