Mechanical properties and morphology of biodegradable poly(lactic acid)/poly(butylene adipate-co-terephthalate) blends compatibilized by transesterification

Biodegradable poly(lactic acid) (PLA)/poly(butylene adipate-co-terephthalate) (PBAT) blends with various tetrabutyl titanate (TBT) concentration were prepared through melt-extrusion. Mechanical properties and morphology were characterized in terms of tensile and impact testing, dynamical mechanical analysis and scanning electron micrograph (SEM). The results indicated that the overall mechanical properties (including tensile strength, elongation at break, toughness and stiffness) of PLA/PBAT blends can be improved significantly after the incorporation of TBT. The SEM micrographs demonstrated that the compatibility and strong interaction between PLA and PBAT was improved via transesterification during melt-extrusion. The interfacial debonding, pullout of PBAT, yielding deformation were the most important mechanisms to improve toughness.

► Compatibility between PLA and PBAT is improved through transesterification.
► Elongation at break of PLA was up to almost 300%.
► Both toughness and stiffness of PLA/PBAT blends are improved significantly after the incorporation of TBT.