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

Conductive powders comprised of coal gasification fine slag porous microbeads/antimony-doped tin oxide nanoparticles (Sb–SnO 2 /CM, ATCM) have been prepared via acid leaching and coating. The lowest powder volume resistivity of 2.6 × 10 3  Ω cm was obtained upon leaching in 20% HCl and coating with a 30 wt% solution of Sb–SnO 2 (pH = 1, Sn/Sb = 6:1). Subsequently, we prepared a 20 wt% ATCM/polypropylene (PP) composite with a volume resistivity of 4.93 × 10 9  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–SnO 2 , and Sb–SnO 2 @TiO 2 , 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–SnO 2 @TiO 2 ), and mechanical strength (equal to Sb–SnO 2 ). These good performances were found to be derived from the unique ATCM structure with Sb–SnO 2 nanoparticles deposited onto the mesopores and surface of CM. This structure prevents the agglomeration of Sb–SnO 2 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.