Effect of the addition of sepiolite on the morphology and properties of melt compounded PHBV/PLA blends

Abstract

A study concerning the incorporation of sepiolite in blends of biopolyesters (PHBV/PLA) to obtain clay/polymer nanocomposites (CPN) was performed to improve the gas barrier performance of the final materials and achieve a well dispersed morphology by means of an increase in the melt viscosity during melt blending. The latter is relevant to increase the stability of the PHBV sheets during thermoforming. The samples were analyzed using scanning electron microscopy (SEM), wide angle X‐ray diffraction (WAXS), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), tensile tests at room and high temperatures, dynamo‐mechanical thermal analysis in torsion mode (DMTA), oscillatory rheometry with a parallel plate setup, Vicat softening temperature system and oxygen barrier properties. The resulting Sepiolite/PHBV/PLA nanocomposites not only improved the compatibility between the biopolymers and reduced the oxygen permeability, but also improved the mechanical properties at room temperature, showing an increase in the elongation at break, as well as increasing the rigidity and stability of the CPN at higher temperatures, which could make them very attractive for uses in thermoforming applications for food packaging. POLYM. COMPOS., 40:E156–E168, 2019. © 2017 Society of Plastics Engineers