Factor analysis on property enhancement of electrically/thermally conductive composites by continuous forced assembly

Abstract

Currently, with the development of many important fields such as aerospace and automotive industries, polymer composites have become an indispensable part of these fields. As for preparation methods, common methods like hot pressing make composites difficult to achieve continuous production. This paper proposed the continuous forced assembly (CFA) and designed continuous production facility, which can achieve the continuous preparation of low filler content (30 wt%) composites with high electrical/thermal conductivity. Besides, we structurally designed roll pressing device and explored its effect on the machining process. Here, short cut carbon fiber (SCF) and solid silica gel (MVQ) are used as electrically/thermally conductive filler and polymer matrix respectively, and continuous preparation of functional composites is completed by CFA method. Compared to the thermal conductivity (1.186 W/(m·K)) of SCF/MVQ composites prepared with lower viscosity matrix (MVQ‐A), the thermal conductivity of composites prepared with high viscosity matrix (MVQ‐D) reached 2.230 W/(m·K). Meanwhile, the process is optimized to explore the effects of the “accordion folding” and “pre‐stretch” methods on the thermal conductivity of composites, the thermal conductivity is converted from in‐plane to vertical direction. In addition, under the same filler content, 2 wt% rGO is beneficial in enhancing the electrical/thermal conductivity of prepared composites. The electrical conductivity and thermal conductivity of SCF28/rGO2/MVQ composite reach 663 S/m and 2.82 W/(m·K), which is higher than that of the properties of SCF/MVQ composite with the same filler content. To sum up, CFA facilitates continuous production of composites, which can be used in thermal management materials (TMMs).Highlights Compared with the “pre‐stretch” method, the thermal conductivity of SCF/MVQ composites prepared by “accordion folding” has a significant improvement. The SCF/rGO/MVQ composites prepared by CFA method show superior thermal conductivity and electrical conductivity. Composites prepared by CFA method can realize the continuous preparation of functional materials.