Properties of Ternary Blends of Compostable PLA/PBAT/PBS

Compostable plastics such as Poly (lactic acid) (PLA), Poly(butylene succinate) (PBS) and Poly(butylene adipate-coterephthalate) (PBAT) have been extensively used in many applications, from commodity to engineering ones. These plastics offer the circularity of the carbon cycle. However, each of them has advantages and disadvantages. The ternary blend of these three are therefore very interesting in terms of phase morphology and their physical properties while offering compostable practices. In this work, the blends of PLA/PBAT/PBS were studied. PLA/PBAT was fixed at 50/50 whereas PBS was varied from 10 to 40 % wt. In order to ensure the compatibility, peroxide and carbodiimide compounds were used. The results show an immiscibility of PLA/PBAT/PBS blend, with continuous surface of PLA and PBAT while PBS is dispersed phase. However, it shows the better interfacial adhesion of PLA/PBAT/PBS when reactive compounds were added. The mechanical properties indicated the modulus of all blends higher than neat PBAT (~52 MPa) and PBS (~377 MPa). However, it insignificantly changed when increased PBS contents, similar to the tensile strength results.