Preparation of carbon black/graphene nanosheets/PP composites with 3D separated conductive networks based on selective laser sintering

Abstract

AbstractThe main research goal of high‐performance conductive polymer composites is to improve electrical conductivity and reduce the percolation threshold. Designing an effective conductive network is one of the fundamental ways to improve the conductivity. In this study, polypropylene composite powders coated with carbon black (CB) and graphene nanosheets (GNSs) were prepared by a combination of ultrasonic dispersion and liquid‐phase deposition, and sintered using a selective laser sintering process to prepare polypropylene composites with three‐dimensional separated conductive networks. The synergistic effect of binary compound fillers of CB and GNSs was utilized to further improve the electrical conductivity of the composites. When the filler loading was 2% and the ratio of CB to graphene was 7:3, the electrical conductivity of the polypropylene composite was 1.315 × 10−3 S/m, which was eight orders of magnitude higher than that of pure polypropylene. In addition, the tensile strength and elongation at break of CB/GNSs/PP composites were improved by 36.4% and 20.77% with excellent mechanical properties. The effects of fillers on the SLS process, thermal stability, melting, and crystallization behavior of the composites were investigated. This study provides an effective and feasible strategy for the preparation of high‐performance conductive polymer composites using SLS 3D printing process.