Elaboration, morphology and properties of starch/polyester nano-biocomposites based on sepiolite clay

• The sepiolite behaviour in TPS/PBAT nano-biocomposites was evaluated.
• Was achieved a good dispersion of sepiolite clay in the samples.
• Sepiolite improved the mechanical properties of the nano-biocomposites.
• Structural and morphological properties were not influenced by the sepiolite addition.
• Blends with better properties were obtained which represent a promising material.

The incorporation of nano-sized sepiolite clays into thermoplastic starch/poly(butylene adipate-co-terephthalate) (TPS/PBAT) blends has been investigated with the goal of improving the matrix properties. TPS/PBAT nano-biocomposites were elaborated with two different proportions of the polymeric phases. The influence of the sepiolite nanoclays on the mechanical, thermal and structural properties of the corresponding blends was evaluated. SEM images confirmed the good dispersion of the sepiolite clay, with a low occurrence of small aggregates in the polymeric matrix. Wide-angle X-ray diffraction showed no significant alteration of the crystalline structures of PBAT and starch induced by the sepiolite clay. The addition of sepiolite slightly affected the thermal degradation of the nano-biocomposites; however, the mechanical tests revealed an increase in some mechanical properties, demonstrating that sepiolite is a promising nanofiller for TPS-based materials.