Preparation of hybrid colloidal graphite-copper phthalocyanine and their utilization in polymer composites with enhanced thermal conductivity and mechanical properties

Abstract

Colloidal graphite-copper phthalocyanine (CG-CuPc) hybrid material was synthesized as a conducting additive to improve the properties of phthalonitrile-terminated polyarylene ether nitriles (PEN-t-ph) polymer composites. These colloidal graphite (CG) was modified with 3-Aminophenoxyphthalonitrile through the catalysis of copper ions by solvothermal processing, which is aimed to increase the adhesion between filler and polymer matrix as well as minimize the interfacial phonon scattering. Scanning electron microscopy (SEM), fourier transform infrared spectroscopy (FTIR), and UV-vis spectroscopy were employed to characterize the as-synthesized CG-CuPc. The results indicated that the CuPc grew successfully on the surface of CG. And the content of CuPc was calculated to be 19.77 wt% with thermal gravimetric analyses (TGA) testing. Subsequently, the hybrid CG-CuPc was introduced to the high-performance PEN-t-ph. Typical SEM images reveal the interface between the filler and surrounding matrix is fuzzy and relatively coherent. As expected, the remarkable enhancement in thermal conductivity of the composites was achieved with flexibility maintained. The thermal conductivity (κ) of sample with 16 wt% CG-CuPc reached the maximum value (0.597 W/(mK)), with a 80 % increase compared to the pure polymer. The TGA curves indicated that all sample showed excellent thermal stabilities with initial degradation temperature (T_id) above 490 °C. Apart from the thermal analysis, the mechanical testing reveals that the tensile strength increased from 79 MPa for pure PEN-t-ph to 86 MPa for PEN-t-ph/CG-CuPc composite with 5 wt% CG-CuPc filler loading.