Improving Dispersion and Mechanical Properties of Polypropylene/Graphene Nanoplatelet Composites by Mixed Solvent-Assisted Melt Blending

Abstract

To improve the dispersion of graphene nanoplatelet (GNP) in polypropylene (PP), GNP was exfoliated in a mixed solvent of p-xylene and N,N-dimethylformamide (DMF) and the exfoliation of GNP was maintained by the addition of a compatibilizer before the melt blending. The concentration of the dispersed GNP in various ratios of the mixed solvents was measured in order to confirm the effect of the mixed solvent on the pre-treatment process. As a compatibilizer for the composite, pyrene-functionalized maleic anhydride-grafted polypropylene (Py-PP) was synthesized. The dispersion state of the composites was analyzed by the three dimensional non-destructive X-ray micro-computed tomography (3D micro-CT). The improved dispersion of GNP resulted in a significant enhancement in the mechanical properties. Young's modulus of PP composites with 2 wt% GNP has increased by 43% compared with that of PP. These results are attributed not only to the improved interfacial interaction between PP and GNP, but also to the homogeneous dispersion state of the GNP in the matrix.

Hybrid solid sensitive arrays/polypropylene composites: A study on sensing alkaline vapors

“…For the better‐dispersed sensor, this coherency is lost through interactions, which greatly affects the tensile properties of the brittle material, which agrees with the results obtained for PP composites with an elevated content of talc as a filler 65 . These results agree with those reported for PP composites creating GNP dispersions 62 : μCT imaging of these composites revealed that when GNPs are poorly dispersed, they tend to aggregate in the matrix, significantly reducing the mechanical properties. A more evenly distributed system was achieved by utilizing a compatibilizer, resulting in a much more stable composite.…”

“…61 Lee el. al 62 studied different methods of mixing GNP and PP. Directing the mixing of components by melting and blending and by applying solvents and a F I G U R E 1 Stress-strain curves for PP and the composites compatibilizer of the components was performed to improve the dispersion of graphene nanoplatelets (GNPs) in PP.…”

“…These reports bring an interesting comparison, as convergence to brittle composites occurs when a rigid filler is merged with PP, mostly due the poor adhesion and dispersion of the filler in the matrix 62,67 ; the inclusion of a compatibilizer agent assisted in both issues. Here, we achieved a good dispersion with the polymericbased sensitive elements without any auxiliary agents, which suggests poor interfacial adhesion between the sensors and PP as the factor responsible for the poor tensile properties.…”

Graphene nanoplatelet/cellulose acetate film with enhanced antistatic, thermal dissipative and mechanical properties for packaging

“…By contrast, introducing the targeted polymer during graphene exfoliation enables the well-dispersion of graphene and thereafter improves the properties of the composite produced, hence being distinguished as one of the most promising approaches to fabricate graphene-based composites. For instance, the use of melt-blending to assist the dispersion of graphene in polypropylene provides the obtained composite an increase of 43% in Young’s modulus (Lee et al 2020 ). The liquid exfoliation of graphite in the presence of sodium carboxymethyl cellulose gives a better dispersion of graphene as well as a higher capacity of the composite produced than that of the commercial graphite in Li-ion (Naboka et al 2016 ).…”

Graphene Nanoplatelet/Cellulose Acetate Composite Film with Simultaneously and Significantly Enhanced Antistatic, Thermal Dissipative and Mechanical Properties for Packaging

“…By contrast, introducing the targeted polymer during graphene exfoliation enables the well-dispersion of graphene and thereafter improves the properties of the composite produced, hence being distinguished as one of most promising approaches to fabricate graphene-based composites. For instance, the use of melt-blending to assist the dispersion of graphene in polypropylene enables the obtained composite an increase of 43% in Young's modulus (Lee et al 2020). The liquid exfoliation of graphite in the presence of sodium carboxymethyl cellulose gives a better dispersion of graphene as well as a higher capacity of the composite produced than that of the commercial graphite in Li-ion (Naboka et al 2016).…”