Development of thermally conductive and high-specific strength polypropylene composites for thermal management applications in automotive

Abstract

This study reports the preparation of multifunctional hybrid composites based on polypropylene (PP) for potential thermal management applications in automotive. Short carbon fiber (CF) at 5 and 8 wt%, and silane-treated hollow glass microsphere (HGM) at 5, 10, 20, 30, and 40 wt% were incorporated separately in PP along with maleic anhydride-grafted-polypropylene (MA-g-PP). The interplay of filler content and its dispersion and distribution had a significant effect on the thermal conductivity (Kc) of the composites. Highest Kc of 1.20 W/m K was obtained for a CF and HGM wt% of 5 and 20, respectively. The rheological analysis revealed improved flowability as the complex viscosity of composites up to 20 wt% of HGM content was found to be less than PP. The thermal stability improved upon HGM incorporation and the highest thermal stability of ~26°C higher than that for PP was exhibited by hybrid composite with 8 wt% CF and 40 wt% HGM. Furthermore, Nielsen model demonstrated to be the closest fit for the experimental thermal conductivity value of hybrid composites among various micromechanical models used. © 2021 Society of Plastics Engineers