Poly(Lactic Acid): Recent Stereochemical Advances and New Materials Engineering

Poly(lactic acid) (PLA) is a representative biobased and biodegradable aliphatic polyester and a front-runner among sustainable materials. As a semicrystalline thermoplastic, PLA exhibits excellent mechanical and physical properties, attracting considerable attention in commodity and medical fields. Stereochemistry is a key factor affecting PLA's properties, and to this end, the engineering of PLA's microstructure for tailored material properties has been an active area of research over the decade. This Review first covers the basic structural variety of PLA. A perspective on the current states of stereocontrolled synthesis as well as the relationships between the structures and properties of PLA stereosequences are included, with an emphasis on record regularity and properties. At last, state-of-the-art examples of high-performance PLA-based materials within an array of applications are given, including packaging, fibers, and textiles, healthcare and electronic devices. Among various stereo-regular sequences of PLA, poly(L-lactic acid) (PLLA) is the most prominent category and has myriad unique properties and applications. In this regard, cutting-edge applications of PLLA are mainly overviewed in this review. At the same time, new materials developed based on other PLA stereosequences are highlighted, which holds the potential to a wide variety of PLA-based sustainable materials.