Comparison of recently developed toughening strategies for polylactic acid blends

The biodegradability of plastics has become a primary requirement for society in the future and sustainable engineering technologies. Among the biodegradable polymers, polylactic acid (PLA) is currently the material of choice due to being relatively inexpensive and having good physical properties. However, its mechanical properties still lag behind those of common synthetic polymers, and brittleness is one of the major concerns for its applicability. Recently, many toughening strategies for PLA have been attempted, and a comparative analysis of them is urgently needed. In this review, we compare the most recent publications and intuitively uncover the key fundamental directions in this area. In particular, although a simple evaluation has many difficulties due to the different testing and processing methods used in the studies, the impact strength, tensile strength, and modulus of PLA after various PLA-toughening strategies are compared in detail. The understanding of PLA-toughening strategies provided by this review could help the future development of biodegradable plastics in general.