Effective regulation of thermal conductivity of polyetherimide/low–melting–point alloy composites based on the construction of segregated structure

Recently, it has been reported that low-melting-point alloy (LMPA) are used in thermal management materials, which has greatly attracted the attention of researchers due to their excellent thermal conductivity and electrical conductivity. However, there is rare report on how to construct the segregated structure of the LMPA network in the polymer matrix for more efficiently improving its thermal conductivity. Here, the polyetherimide/SnBi17Cu0.5 LMPA (PEI/SBC) composites with segregated structure were obtained which SnBi17Cu0.5 particles enclosed by PEI microspheres were interconnected forming a continuous network structure. Therefore, the PEI/SBC composites with 50 vol% SBC had a satisfied thermal conductivity of 1.26 Wm-1K−1. The influence factors on the LMPA segregated structure were systematically investigated. It showed that hot-processing temperature and size of the LMPA particles determined the formation of segregated structure. Besides, the small size of the PEI microspheres was favor of the densification of polymer matrix.