Facile modification of organoclay and its effect on the compatibility and properties of novel biodegradable PBE/PBAT nanocomposites

Facile and green modification of organoclay by stearic acid (SA) to obtain a toxicity-free expanded organoclay (EOC) was realized. Biodegradable nanocomposites were prepared from a novel Natureplast PBE 003(PBE)/poly(butylene adipate-co-terephthalate)(PBAT) blend (80/20) with various EOC contents by melt compounding. The modification process of EOC was confirmed by X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). The compatibility and nanodispersion state of investigated samples were performed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The degree of crystallinity of PBE and its filled blends was studied using differential scanning calorimetry (DSC) and the results showed that its crystallinity was hindered with the addition of both PBAT and EOC. The influence of the EOC content on the compatibility and nanodispersion with PBE/PBAT blends was characterized using dynamic mechanical analysis (DMA), tensile and water vapor permeability (WVP) properties. DMA data exhibited that the storage modulus obviously increased with increasing EOC content, especially in the case of PBE/PBAT/EOC15 as compared to pristine PBE or PBE/PBAT blend. The deformation state of the samples was monitored during the DMA test and evidenced that the blend was deformed at 110 C-circle , whereas the filled blends didn't deform until 150 C-circle. Moreover, a good correlation between tensile and WVP barrier properties for PBE bio-nanocomposites was observed, especially up to 5 wt.% EOC that can be candidate for food packaging and biomedical applications. Biodegradability tests were performed in aqueous medium. (C) 2016 Elsevier Ltd. All rights reserved.