STRUCTURE AND MORPHOLOGY OF SMALL-DIAMETER ELECTROSPUN ARAMID FIBERS

Very small diameter fibers of poly(p-phenylene terephthalamide) (PPTA) ranging in diameter from 40 nm to a few hundreds of nanometers were m ade by the electrospinning process. The fibers have a circular cross-s ection, are birefringent and stable at temperatures greater than 400 d egrees C. Electron diffraction patterns obtained from both as-spun and annealed fibers show meridional and equatorial reflections demonstrat ing order in the material. The crystal structure and morphology of the fibers were characterized using bright and dark field electron micros copy, electron diffraction and atomic force microscopy.