(230e) Biopolymer – Thermally Reduced Graphene Nanocomposites: Structural Characterization and Properties

Nanocomposites of poly-L-lactide (PLA), bio-polyamide (PA) and poly(butylene adipate-co-terephthalate) (PBAT) with varying amounts of thermally reduced graphene were generated by melt mixing. Structural characterization to analyze the effect of graphene on chain conformations, crystallinity, interfacial interactions as well as properties was performed. Free amide bonds in the amorphous phase of PA underwent chemical reaction in the presence of graphene oxide.  Strong hydrogen bonding and van der Waals interaction between graphene oxide and PA chains also resulted in transition from the disordered to ordered state. Due to the better interfacial interactions of PA chains with graphene surface, these nanocomposites were also observed to have exfoliated morphology, whereas PLA nanocomposites had least exfoliation. At 5% GO content, the Young’s modulus of PA nanocomposites was 1.8 times as compared to pure polymers, whereas the increment was 1.4 and 1.1 for PLA and Ecoflex nanocomposites. The PA nanocomposites were also observed to have maximum extent of enhancements in storage modulus, even at higher temperatures. A significant increase in the melt enthalpy of PA was observed on graphene oxide incorporation which confirmed the findings from structural studies.