Microstructure effects on the rheology of nanoclay‐filled PHB/LDPE blends

The rheological and morphological properties of the nanoclay‐filled LDPE/PHB blends using LDPE‐g‐MAH as compatibilizer were determined. SEM data showed that the morphology was more sensitive to organoclay incorporation, compared to inclusion of the compatibilizer. Moreover, the results of image analysis and rheological studies indicated that nanoclay was located in the PHB phase after migrating from the LDPE phase, due to the thermodynamic and viscosity effects. The data obtained also showed that the stabilization mechanisms of PHB and LDPE matrix nanocomposites is due to coalescence prevention (due to the physical barrier) and alteration in the viscosity ratio of the phases, respectively. The obvious, pseudo‐solid‐like behavior over a wide range of frequencies in the PHB/LDPE/nanoclay systems demonstrated that the strong interaction between PHB/LDPE and nanoclay restricted the relaxation process of polymer chains. Therefore, PHB/LDPE/nanoclay was associated with a greater melt strength, which is essential for its favorable processability and applications. POLYM. COMPOS., 40:4125–4134, 2019. © 2019 Society of Plastics Engineers