MATERIALS
Polypropylene-Polycarbonate composites with graphene oxide nanosheets: synthesis and characterization
Herein the effect of graphene oxide nanosheets (GOSs) on the thermo-mechanical stabilities of polypropylene (PP)/polycarbonate (PC), polymer blend nanocomposites (PNCs) fabricated via melt compounding has been explored. The comparison of properties of pure blend with PNCs, pointed out whether the mixing sequences have any effect on thermo-mechanical stabilities of PNCs. The PP/PC/GO nanocomposite exhibited an excellent increment in tensile strength and melting temperature as compared to the neat blend. In contrast, the PC/GO/PP nanocomposite, prepared by mixing the GOSs with PC first and then PC/GO with PP, has lower thermo-mechanical stability than PP/PC/GO. Interestingly, PP/GO/PC nanocomposite prepared by mixing the GOSs with PP first and then PP/GO with PC, showed the highest improvement in thermo-mechanical stability as compared to pure blend, PP/PC/GO, and PC/GO/PP. We attribute this trend of stabilities for PNCs due to the different extent of GOSs distributions within the polymer matrix. For PP/PC/GO, the GOSs were effectively dispersed in the PP phase due to low viscosity. In the case of PC/GO/PP, only small amount of GOSs was localized in PP and most of GOSs remain in PC phase. However, in case of PP/GO/PC, almost all GOSs were dispersed homogeneously in both phases resulting in a distinct increment of thermo-mechanical stabilities.