Synthesis of PA12/functionalized GNP nanocomposite powders for the selective laser sintering process

In an effort to fabricate prototypes with improved mechanical properties in the selective laser sintering process, functionalized graphite nanoplatelets were added to polyamide-12 powder to produce a nanocomposite powder. The polyamide-12 powder was chosen as the matrix polymer because it has features conducive to laser sintering, such as a low melting temperature and high mechanical properties. As fillers, the graphite nanoplatelets were oxidized through a nitric acid treatment to improve the interfacial bonding. For the syntheses of the nanocomposite solution, intercalation in an autoclave was conducted to obtain good dispersion and manufacturability. The micro/nanostructures of the synthesized nanocomposites were examined through scanning electron microscopy. The distribution of particles was also analyzed to look at the feasibility for the selective laser sintering process. The synthesized nanocomposite powder was layered and sintered by a laser. The mechanical properties for specimens made of neat polyamide-12, polyamide-12/TiO2, and polyamide-12/functionalized graphite nanoplatelet were tested and compared. The results indicate that the functionalization of nanofiller reinforces interfacial bonding force. For this reason, a small amount of nanofiller, which does not influence the thermal and rheological behavior, can improve the material properties.