▎ 摘　　要

In this work, hybrid polypropylene (PP)-based composites reinforced with graphene nanoplatelets (GnPs) and glass fiber (GF) were fabricated by injection molding to elucidate how the hybrid approach can produce synergistic effects capable of achieving properties and functionalities not possible in biphasic composites. Synergism between the reinforcements translated to improved mechanical performance, which was attributed to the chemically and/or electrostatically assembled hierarchical structure that facilitates load transfer at the interface while simultaneously tailoring the crystalline microstructure of the matrix by inducing transcrystallization and beta-crystal formation. It was demonstrated that there exists an optimal concentration of 0.5 wt % GnP, producing the greatest mechanical properties and synergistic effect, corresponding to the highest degree of crystallinity (similar to 6% greater than Neat PP) and peak formation of beta-crystals within the PP matrix. The greatest synergistic effect was found to be similar to 52 and similar to 39% for the specific tensile strength and flexural strength, respectively. The same optimal concentration of GnPs was found to produce the highest synergistic effect for thermal conductivity of similar to 68% due to the volume exclusion effect induced by the GFs combined with the higher crystallinity of the microstructure, promoting the formation of thermally conductive pathways. Ultimately, the mechanisms contributing to the synergistic effect presented in this work can be used to maximize the performance of hybrid synergistic presented performance hybrid composite systems, giving them the potential to be tailored for a variety of high-performance industrial applications to meet the rising demands for ultra-strong, thermally conductive, and lightweight materials.