Enhanced properties of phthalonitrile-terminated polyarylene ether nitriles embedded with hybrid MWCNT-boehmite nanocomposites

Abstract

The main motivation of the present work was to fabricate novel multifunctional polymer-based nanocomposites. The nanocomposites embedded with multi-walled carbon nanotube-boehmite (MWCNT-boehmite) were prepared via hot pressure casting technique. The MWCNT coated with boehmite were synthesized by hydrothermal synthesis. Subsequently, as-prepared MWCNT-boehmite was added into the phthalonitrile-terminated polyarylene ether nitriles (PEN-t-CN) matrix in order to benefit from the synergetic effect of MWCNT and boehmite. Scanning electron microscopy (SEM), transmission electron microscopy (TEM) X-ray diffraction (XRD), and Fourier transform infrared (FTIR) were employed to confirm the existence of MWCNT-boehmite in our article. Furthermore, the structures, fracture morphologies, thermal, mechanical and dielectric properties of the nanocomposites were investigated, respectively. SEM images indicated that the MWCNT-boehmite was homogeneously dispersed in the polymer, which acted as an essential factor to ensure good physical properties. The TGA analysis showed that the incorporation of MWCNT-boehmite enhanced the thermal stability of the nanocomposites with initial degradation temperature (Tid) increasing from 458 to 492°C, while that of the pure PEN-t-CN was 439°C. The mechanical testing proved that significant enhancement of mechanical properties has been achieved. The tensile strength of PEN-t-CN/MWCNT-boehmite composites with 3 wt% MWCNT-boehmite reached the maximum (78.33 MPa), with a 41.7 % increase compared to the pure polymer. More importantly, the unique dielectric properties were systematically discussed and the results demonstrated that dielectric properties exhibited little dependency on frequency. For the incorporation of hybrid filler, the positive impact of MWCNT-boehmite hybrid material resulted in polymer-based nanocomposites with enhanced physical properties.