Dielectric and piezoelectric properties in selective laser sintered polyamide11/BaTiO3/CNT ternary nanocomposites. (5th April 2018) - Qi, Fangwei
Abstract: Polyamide11 (PA11)/BaTiO3 /carbon nanotube (CNT) ternary nanocomposites (PBCNCs-3D) with 3D segregated percolation routes were fabricated by selective laser sintering (SLS) of CNT-coated PA11/BaTiO3 nanocomposite powder. The CNT-coated PA11/BaTiO3 nanocomposite powder show a higher laser absorption and wider sintering window than those of conventional PA11/BaTiO3 /CNT ternary nanocomposite powders with a structure where CNTs are randomly distributed throughout the powder particles, endowing the composite powders with better sinterability. The 3D segregated conductive pathway was efficiently constructed in the PBCNCs-3D parts with a low percolation threshold of 0.3 wt%. The PBCNCs-3D parts showed a higher dielectric constant of 16.2 at a frequency of 1 kHz, which is approximately twice higher than that of SLS-printed composite parts (PBCNCs) without a segregated structure. Compared with PBCNCs, the piezoelectric strain coefficient increased from 1.7 to 2.1 pC/N. These results not only provide a new material for SLS processing but lay the groundwork to enhance the performance of piezoelectric polymer composites by constructing 3D segregated percolation routes. Graphical abstract: Highlights: CNT-coated PA11/BaTiO3 composite powder was prepared for selective laser sintering. This composite powder endowed polymer with an enhanced laser sintering performance. 3D segregated percolation routes are formed in composites by selective laser sintering of this composite powder. The composites with segregated structure have enhanced electrical properties. The results clear the way for enhancing the performance of piezoelectric polymer composites.