Mechanical and tribological properties of electrospun PA 6(3)T fiber mats

Abstract

(G. C. Rutledge). AbstractThe mechanical and tribological properties of electrospun fiber mats are of paramount importance to their utility as components in a large number of applications. Although some mechanical properties of these mats have been reported previously, reports of their tribological properties are essentially nonexistent. In this work, electrospun nanofiber mats of poly(trimethyl hexamethylene terephthalamide) (PA 6(3)T) with average fiber diameter of 463±64 nm are characterized mechanically and tribologically. Post-spin thermal annealing was used to modify the properties of the fiber mats.Morphological changes, in-plane tensile response, friction coefficient and wear rate were characterized as functions of the annealing temperature. The Young's moduli, yield stresses and toughnesses of the nonwoven mats improved by two-to ten-fold when annealed slightly above the glass transition temperature, but at the expense of mat porosity. The coefficient of friction and the wear rate decrease by factors of two and ten, respectively, under the same conditions. The wear rate correlates with the yield properties of the mat, in accord with a modified Ratner-Lancaster model. The variation in mechanical and tribological properties of the mats with increasing annealing temperature is consistent with the formation of fiber-to-fiber junctions and a mechanism of abrasive wear that involves the breakage of fibers between junctions.

Permeability of electrospun fiber mats under hydraulic flow

“…A vertically aligned, parallel plate setup was used for electrospinning, as described elsewhere [24]. …”

“…The as-spun mats were annealed thermally in a furnace (Thermolyne Industrial Benchtop Furnace, FD1545M) to strengthen the electrospun mat, as previously reported [24]. The mats were held in plane during the annealing process by draping over a petri dish that is 10 cm in diameter.…”

Thermoregulated gas transport through electrospun nanofiber membranes

“…To form thee-layered composite membranes, a nonwoven electrospun PS or PS:PSU mat was sandwiched between two electrospun nonwoven CA mats and hotpressing at 80 °C under 4,000 lbs load for 5 min, as described elsewhere (Mannarino and Rutledge, 2012). Disks (3.7 cm in diameter) were cut from the three-layered membranes and sandwiched between two pieces of aluminum tape (Han and Martin, 2009) having circular openings to expose an effective membrane area of 0.95 cm 2 .…”

Spray‐Layer‐by‐Layer Carbon Nanotube/Electrospun Fiber Electrodes for Flexible Chemiresistive Sensor Applications

“…Parallel-plate electrospinning apparatus ( Figure 1a) was used to create flexible nonwoven mats of polysulfone fibers (average fiber diameter of 1.69 ± 0.17 µm and mat thickness = 103 ± 2 µm, Figure 1b) from organic polymer solutions using a protocol Submitted to 6 6 modified from a previous report. [13] Polysulfone was chosen as a polymer substrate because it has high chemical resistance and good thermal and mechanical stability. [14] The nonwoven mats have an inherently high porosity of 85.1 ± 1.1%, which was determined by a gravimetric method described elsewhere.…”

“…[14] The nonwoven mats have an inherently high porosity of 85.1 ± 1.1%, which was determined by a gravimetric method described elsewhere. [13] Once the ES fiber mat was generated, it was first treated with one minute of air plasma to improve the wettability by introducing hydroxyl and charged carboxylated groups on the surface. [15] The ES fiber mat was then immediately immersed into a 0.2 wt.% aqueous solution of branched polyethylenimine (BPEI) for 10 min to impart positive charge on the surface of ES fibers.…”