Microstructure, thermomechanical properties, and electrical conductivity of carbon black-filled nylon-12 nanocomposites prepared by selective laser sintering

Selective laser sintering (SLS) is employed to fabricate a multifunctional polymer nanocomposite comprising Nylon-12 reinforced with carbon black (CB) at a loading of 4% by weight. The heat distortion temperature (HDT), viscoelastic properties, and the electrical conductivity of this nanocomposite are compared to those obtained via extrusion injection molding (Ex-IM). The HDT of the nanocomposites made by the two methods are found to be nearly identical. The electrical conductivity of the nanocomposite made by SLS is five orders of magnitude higher than that obtained through Ex-IM. The storage modulus of the SLS-processed nanocomposite is at least one order of magnitude higher than that of the nanocomposite made by Ex-IM, for all the frequencies tested. The observed differences in properties and the effects of the processing methods on the polymer's molecular weight, its crystallization characteristics, and the dispersion of CB within the polymer matrix are investigated using X-ray diffraction, differential scanning calorimetry, and scanning electron microscopy. POLYM. ENG. SCI., 2012. (C) 2011 Society of Plastics Engineers