Construction of “core–shell” structure for improved thermal conductivity and mechanical properties of polyamide 6 composites

Polymer-based thermal management composites have been widely utilized in the electronics industry for heat dissipation. Filled with thermal conductive fillers, binary blend polymer-based composite can obtain higher thermal conductivity than single polymer-based composite, however, with impaired mechanical performances. In this study, a tailor-made “core–shell” structure based on high-density polyethylene (PE), high-density polyethylene grafted with maleic anhydride (PE-g-MA) and multiwalled carbon nanotubes (CNTs) was fabricated and introduced into boron nitride (BN) filled polyamide 6 (PA6). In the “core–shell” structure, PE domains acted as the “core,” while CNTs and CNTs-localizing PE-g-MA constituted the “shell.” As-fabricated composite exhibited thermal conductivity of 1.65 W/m K, which was 36.5% higher than that of PA6/PE/BN composite at the same BN loading, and maintained excellent electrical insulating. Meanwhile, benefited from the novel “core–shell” structure, the mechanical properties of PA6/PE-g-MA/PE/CNTs/BN composite were comprehensively balanced.