Selective localization of rice husk derived graphene in reactive compatibilized PP/PA6 blends: Influence on morphology, interface and mechanical properties

Graphene is synthesized and characterized using rice husk as a source with carbonization and potassium hydroxide (KOH) activation process. It has functional groups at the edges with a smooth surface. Graphene is melt-mixed with 50/50 (wt/wt) polypropylene (PP)/polyamine-6 (PA6) in the presence and absence of a compatibilizer. The compatibilizer used is polypropylene grafted maleic anhydride (PP-g-MA). There is a reaction between PP-g-MA and PA6 phase as established from FTIR spectroscopy. All samples show the formation of complex morphology with compatibilization and graphene addition in 50/50 (wt/wt) PP/PA6 blend. Graphene is localized in PA6 phase of 50/50 (wt/wt) PP/PA6 blend and its nanocomposites in the presence and absence of PP-g-MA. All the samples have power-law index (n) value of less than one exhibiting pseudoplastic fluid behavior; n values are significantly higher after compatibilization and graphene addition in 50/50 (wt/wt) PP/PA6 blend as reveals from rheological measurements. Graphene addition influences the crystallization behavior with selective localization in PA6 phase and morphology development. Dynamic mechanical analysis (DMA) shows improved stiffness of 50/50 (wt/wt) PP/PA6 blend with an addition of graphene and PP-g-MA. Tensile and impact properties increases are highest with an addition of 1 wt.% of graphene in 50/50 (wt/wt) PP/PA6 blend in presence of PP-g-MA.