Polyamide 11-carbon nanotubes nanocomposites: Processing, morphological, and property characterization

The objective of this research is to develop a multifunctional polyamide 11 (PA11) polymer with enhanced electrical, thermal, mechanical, and flammability properties for selective laser sintering (SLS) rapid manufacturing through the use of nanotechnology. In the present study, a nanophase was introduced into PA11 powder via rotation & revolution and twin screw extrusion techniques to disperse the MWNTs in the PA11 pellet. Arkema Rilsan® polyamide 11 molding polymer pellets were used with 1, 3, 5, and 7 wt% loadings of Arkema's Graphistrength™ multi-wall carbon nanotubes (MWNTs) to create a family of PA11-MWNT nanocomposites using twin screw extrusion technique. Arkema Rilsan® polyamide 11 powders were blended with 5 wt% loading of Graphistrength™ MWNTs using the rotation & revolution technique to create another set of PA11-MWNT nanocomposites. Transmission electron microscopy and scanning electron microscopy were used to determine the degree and uniformity of dispersion of MWNTs in the PA11 polymer. Injection and compression molded test specimens were fabricated for physical, electrical, thermal, mechanical, and flammability properties characterization. Thermal stability of these polyamide 11-MWNT nanocomposites was examined by TGA. Kinetic parameters were calculated using isoconversion technique. Electrical properties were measured using ASTM D257. Mechanical properties such as ultimate tensile strength, rupture tensile strength, and elongation at rupture were measured. Flammability properties were obtained using the UL 94 test method. All these different test methods and subsequent polymer characteristics are discussed in this paper.