Effect of styrene-maleic anhydride on phase morphology and properties of PLA/PBAT blends

Poly(butylene adipate-terephthalate) (PBAT) has outstanding ductility, but its strength is low, then, high modulus of polylactic acid (PLA) can solve the defects of PBAT. The styrene-maleic anhydride (SMA) was used as compatibilizer to prepare poly(lactic acid)/poly(butylene adipate-co-butylene terephthalate) (PLA/PBAT) blends. The effect of the content of SMA on the crystallization performance, thermal performance, rheological behavior and tensile properties of the blends were investigated. The results show that the SMA can significantly reduce the particle size of PLA, and the size of the dispersed PLA phase decreases from 1.75 µm to 0.60 µm when the content of SMA is 1.5wt%. The SMA can increase the crystallinity of PBAT, and as the SMA is added up to 2wt%, the crystallinity reaches up to the maximum value of 9.22%. It is found by the Han curves that low content of the SMA can give rise to closely homogeneous blends, and the elasticity of PLA/PBAT melt increase gradually with the increase in amount of SMA content. Moreover, the SMA enhance the tensile properties of PLA/PBAT blends. As the addition of SMA, the tensile strength and elongation at break both increase first and then decrease. The tensile strength of the composite with 1.5wt% SMA is 21.8 MPa, which is 21% higher than that of the counterpart without SMA (18.1 MPa). The elongation at break reaches the maximum value of 433.7% when SMA content is 1wt%, which is 25% higher than that of the composite without SMA. © 2023 Beijing University of Aeronautics and Astronautics (BUAA). All rights reserved.