Improvement of thermal conductivities and mechanical properties for polyphthalonitrile nanocomposites via incorporating functionalized h- BN fillers

Abstract

In this study, we have prepared a series of composite materials by using a catechol-based phthalonitrile resin as the matrix, and hexagonal boron nitride (h-BN) nanoparticles as the fillers to improve the toughness and thermal conductivity of the matrix. The surface of nanoparticles was modified with the silane coupling agent (KH550) under mild conditions to enhance the interfacial compatibility, which could be confirmed by Fourier transform infrared spectroscopy and thermogravimetric analysis. The thermal conductivities of composites reached 0.79 W (m·K)⁻¹, which was 3.6 times as much as that of the neat resin, and conformed to the Cheng-Vachon model by fitting the measured values into several heat conduction models. The three-point bending test showed that the toughness and strength were improved at the same time and toughening mechanism was explored by using scanning electron microscope. The h-BN nanoparticles can not only improve the thermal conductivity of the resin but also enhance its mechanical properties.