Microstructural and mechanical characterization of PA12/MWCNTs nanocomposite manufactured by selective laser sintering

To determine the potential properties of commercial polyamide 12 (PA12) used in the selective laser sintering (SLS) process, multi-walled carbon nanotubes (MWCNTs) were dispersed in the polyamide powder by mechanical mixing to prepare a composite (PA/MWCNTs). Specimens of PA12 and PA/MWCNTs were manufactured by the SLS process. Infrared spectroscopy, X-ray diffraction and dynamic mechanical analysis were used to assess the structural and mechanical properties of the materials. Stress-strain tests showed higher values for flexural modulus and ultimate strength for the composite when compared to PA12 specimens. Changes in the viscoelastic properties suggest intermolecular interaction between the PA12 and MWCNTs. Fatigue tests show an improvement in the composite strength with the addition of MWCNTs, retarding the creep failure mechanism. (C) 2011 Elsevier Ltd. All rights reserved.