Crystallization, thermal stability, barrier property, and aging resistance application of multi-functionalized graphene oxide/poly(lactide)/starch nanocomposites.

Poly(lactide)-starch matrix, blended with multi-functionalized graphene oxide, was synthesized by solution casting in this study. To improve its interface compatibility, the graphene oxide (GO) was grafted with maleic anhydride and subsequently modified by dodecyl amine. The chemical structure and morphology of functionalized GO (f-GO) were determined by Fourier transform infrared (FTIR) spectroscopy, X-ray photoelectron spectroscopy (XPS), and transmission electron microscopy (TEM). The crystallization property, surface wettability, morphology, thermal stability, and dynamic mechanical and aging resistance properties of the nanocomposite were determined. By XRD and morphological analysis, we observed the formation of well-dispersed nanocomposites. Thermo-gravimetric analysis revealed significant improvements in thermal stability. The isothermal and non-isothermal crystallization behavior of the PLA-starch-f-GO nanocomposites demonstrated that the f-GO that was added accelerated the heterogeneous nucleation of the nanocomposites. The surface hydrophobicity, UV-shielding capacity, and aging resistance properties of these nanocomposites were enhanced by the incorporation of the f-GO. The migration rate of plasticizer of the nanocomposites decreased compared with the group without f-GO. The storage modulus for these nanocomposites improved by dynamic mechanical analysis. These insights provide a strategy for constructing high-performance nanohybrids and broadening their application in the food packaging and pharmaceutical industries.
(Copyright © 2019. Published by Elsevier B.V.)