Preparation and Properties of Enhanced Bio-Based PLA/PA6/Graphene Nanocomposites in the Presence of an Ester–Amide Exchange Catalyst.

Considering the importance of polylactic acid (PLA) biopolymer in industry, in this research we represent a protocol that benefits from the presence of PA6 phase (30 wt%), using an ester-amide exchange catalyst and GN as nanofiller to enhance PLA mechanical properties. To this purpose, it was decided to fabricate blends and nanocomposites in the presence of cobalt(II) acetylacetonate (Cat) as the catalyst. XRD patterns revealed good compatibility of the polymer moieties by broadening of the PLA characteristic peaks and also good dispersion of the GN nanoparticles within the matrix. In the TEM pictures, the GN nanoparticles size ranged from 20 to 130 nm which confirms its good intercalation and exfoliation. T₀ and T_max, considered as thermal stability, of the samples decreased slightly by reactive blending, however, the values were still comparable with them in pure PLA. DSC thermograms and the curves from DMTA exhibited the lower T_g, T_m and crystallinity values of PLA matrix in the alloys and nanocomposites especially in the presence of Cat. Investigation of tensile properties revealed significantly enhanced elongation at break, from 7 in origin PLA to the maximum of 29% in PLA/PA/Cat, with negligible deficiency in modulus, from 2.85 to a minimum of 1.95 GPa, and tensile strength, from 65 to a minimum of 46 MPa, respectively. MFI test results disclosed higher flow-ability of the alloys and composites in compare with neat PLA and also melt flow ratio in two different testing weighs, shows broad molecular weight distribution of the fabricates due to the occurrence of exchange reactions in the presence of Cat. [ABSTRACT FROM AUTHOR]