Utilizing Binary Phase Segregation and Extrusion to Enhance the Electronic Properties of Graphene Nanocomposites

Our goal in this study is to incorporate graphene nanoplatelets (GNPs) in a polymer blend of poly(lactic acid) (PLA) and isotactic polypropylene (iPP) to facilitate the dispersion of GNPs and use the morphology of phase segregation to create a pathway for concentrating GNPs to achieve percolation with lower GNP concentration. Investigating the interfacial properties between PLA/GNPs and iPP/GNPs, we noticed that iPP has a lower contact angle on GNPs compared to PLA on GNPs. This showed a great potential that the GNP are easily confined in iPP rather than in PLA domains or at the PLA/PP interfaces. Utilizing this property, as the PLA content increases, the iPP content decreases, resulting in a reduction of the available space for GNPs. This decrease in space leads to a higher chance for GNPs to accumulate together. Furthermore, through careful control of the concentration in the immiscible blend of PLA/PP, it is possible to achieve a bicontinuous structure. This structure facilitates the creation of a pathway for the fillers, allowing for the use of minimal GNPs while achieving optimal electrical conductivity properties. The PLA/PP/GNPs can be oriented by the shear forces coming from the nozzle that produce a higher performance.