Polyamide 46/multi-walled carbon nanotube nanocomposites with enhanced thermal, electrical, and mechanical properties

Polyamide 46 (PA 46)/modified multi-walled carbon nanotube (m-MWNT) nanocomposites were prepared using a solution mixing technique. The efficient modification of the MWNTs was confirmed by Raman spectrometry with a 0.52 intensity ratio of the D-G bands. Scanning electron microscopy images demonstrated sufficient adhesion between the m-MWNTs and PA 46. Differential scanning calorimetry results illustrated that the m-MWNTs facilitated the nucleation of PA 46 (up to ca. 11 degrees C rise), leading to smaller PA 46 crystallites. Avrami analysis showed a decrease in the dimension of PA 46 crystal growth in the composites because of a nanoconfined/constrained environment formation. The equilibrium melting temperature (T-m degrees) of PA 46 increased in the composites, with an increase of 5.8 degrees C at 3 wt.% m-MWNT loading. The hardness increased to 34% for the composites compared with neat PA 46. An electrical percolation threshold between 2 wt.% and 3 wt.% m-MWNT loading was identified. (C) 2011 Elsevier Ltd. All rights reserved.