Enhancing the electrical and thermal conductivity of polypropylene composites through the addition of Sb–SnO2/coal gasification fine slag porous microbead powder

Abstract

Conductive powders comprised of coal gasification fine slag porous microbeads/antimony-doped tin oxide nanoparticles (Sb–SnO2/CM, ATCM) have been prepared via acid leaching and coating. The lowest powder volume resistivity of 2.6 × 103 Ω cm was obtained upon leaching in 20% HCl and coating with a 30 wt% solution of Sb–SnO2 (pH = 1, Sn/Sb = 6:1). Subsequently, we prepared a 20 wt% ATCM/polypropylene (PP) composite with a volume resistivity of 4.93 × 109 Ω cm, tensile strength of 29.03 MPa, and thermal conductivity of 0.137 W/(m·K), which reached 0.187 W/(m·K) at a 70 wt% loading. When compared with several commercial conductive fillers, such as carbon black, graphene, Sb–SnO2, and Sb–SnO2@TiO2, 20 wt% ATCM/PP has been proven superior or comparable to most of its counterparts in terms of the improved antistatic properties, enhanced thermal conductivity (only lower than Sb–SnO2@TiO2), and mechanical strength (equal to Sb–SnO2). These good performances were found to be derived from the unique ATCM structure with Sb–SnO2 nanoparticles deposited onto the mesopores and surface of CM. This structure prevents the agglomeration of Sb–SnO2 and provides abundant conductive networks. ATCM also shows a decorative light brown color and low cost (15 USD/kg), which are favorable for industrial production. Our results lay a theoretical foundation for the future applications of ATCM.