Thermal behavior of polypropylene composites with segregated graphene nanoplatelet network

Three-dimensional architecture of segregated network can significantly influence thermal behaviors of polymer composites, such as the melting temperature (T_m) and degradation temperature. However, there have been few systematic studies on the thermal behaviors of polypropylene (PP) composites with a segregated network that the fillers were selectively located in the polymeric particle interfaces. In this study, we found that introduction of the segregated graphene nanoplatelet (GNP) network induced the maximum T_m of 177.6°C, extending the operating temperature by 11.5°C compared to the T_m of composites with randomly dispersed GNPs. In contrast, the thermal degradation temperature of polymer composites varied insignificantly regardless of introduction of the segregated network because the thermal degradation of the polymer matrix occurred after the PP chains melted and the segregated GNP network collapsed at temperatures above the T_m. Therefore, the incorporation of a segregated network can be an effective option for enhancing the T_m and extending the operating temperature of the polymer composites. Highlights: Segregated network induced the remarkable increase in melting temperature. Meanwhile, the segregated network had little effect on decomposition temperature. Segregated composite was efficient strategy for expanding operating temperature.