The Effect of Zn ₂ (BDC) ₂ Metal Organic Framework on the Miscibility and Properties of Poly(Lactic Acid)/Poly(Butylene Adipate-co-Terephthalate) Biodegradable Blends

In our research described in this paper, the metal-organic framework MOF-2 [Zn2(BDC)2] was used to enhance the properties of a biodegradable blend based on poly(lactic acid) (PLA) and poly(butylene adipate-co-terephthalate) (PBAT). PLA/PBAT/(1, 3, 5, and 7 wt%) MOF-2 blends were prepared using a melt blending technology with a twin-screw extruder. The phase morphology, rheological behavior and barrier properties of the blends were studied. X-ray diffraction (XRD) showed a slight increase in the crystalline content of the PLA/PBAT matrix with increasing MOF-2 content. Scanning electron microscopy (SEM) revealed that the PLA/PBAT blend was immiscible, and the phase morphology improved with MOF-2 by enhancing the interfacial compatibility, reducing the size of micro-domains and cavities, and promoting a transition to a co-continuous morphology, indicating better miscibility. The ternary nanocomposites with 5 and 7 wt% MOF-2 showed increased complex viscosity (η*) and storage modulus (G′) compared to those with 1 and 3% MOF-2, indicating stronger percolated networks. The thermal and barrier properties and water absorption capacity were also improved, confirming the rheological measurements. All the results showed that the PLA/PBAT/MOF-2 nanocomposites could be used in the field of packaging.