Selective Localization of Nanofiller on Interface of Polymer Composites via Surface Energy Modification to Improve Compatibility of Polymer Blends

Dispersed nanofillers in immiscible polymer blends prevent phase separation and voids formations being localized at the interface of the blends. The nanofillers can improve mechanical properties, however, the aggregation and agglomeration during the mixing process, such as melt blending and extrusion methods. Insufficient dispersion of nanofillers in polymer blend limits the application of blends works as a defect. Therefore, we present the effects of the surface energy of nanofillers on its dispersion and selective localization in the Poly(lactic acid) (PLA)/poly(butylene adipate-co-terephthalate) (PBAT) nanocomposite. Here in, the modified cellulose nanofiber (m-CNF) and modified silica nanofillers (m-SiO2) were used to prevent self-aggregation via hydrogen bonding reducing the surface energy of them. Then, by controlling the blending time, we confirmed that the localization of modified nanofillers in the nanocomposite. As a result, the modified nanoparticles, located at the PLA/PBAT interface, changed the morphology of the PLA/PBAT nanocomposites, thereby significantly improving the tensile strength and elongation at break by approximately 7% and 16%, respectively. Furthermore, the thermal and mechanical properties of composite were comprehensively enhanced regarding the PBAT mixing sequence and selective localization of the nanofiller. It was found that the selective localization of the nanofillers can be utilized to tune the mechanical properties of the PLA/PBAT nanocomposites with respect to their corresponding morphologies. The selective localization of silica nanoparticles in the PLA/PBAT nanocomposite is described in detail, and the melt blending method is presented for achieving the selective localization in an industrial scale to develop eco-friendly packaging films.