Poly(lactic acid) stereocomplexes based molecular architectures: Synthesis and crystallization

• Published in: Progress in polymer science Vol. 146; p. 101742
• Main Authors: Michell, Rose Mary, Ladelta, Viko, Da Silva, Edgar, Müller, Alejandro J, Hadjichristidis, Nikos
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.11.2023
• Subjects: Crystallization; Lactides; Macromolecular architecture; Polylactides; Stereocomplexes; Synthesis; PBAT; TBDMS; DACA; Sn(Oct)2; (SS) LLA; ROMP; CNFs; PLA-sc; D/L-SMP; GOs; Xc; CROP; Tc; Synthesis; DSC; DBU; TBD; Tm; RAFT; PBS; EG; CNCs; Stereocomplexes; EDC·HCl; Macromolecular architecture; Lu; MW; ATRP; EVA; ROP; NA; RF; PCL; MWCNTs; POSS; RCM; rac-LA; PLA; DPP; PDMAEMA; G; NHC; PDLA; DABCO; SC; LDH; α-CD; PLLA; Lactides; Al(OiPr)3; ISN-PLLA/PDLA; DMAP; BnOH; SFN; Polylactides; PPRXs; UPy-OH; Ru; Crystallization; EtGly; TfA; HEMA; IMes; PEG; (RR) DLA; HAP; (RS) m-LA; AlOH; HC; OEGMA; PLOM
• ISSN: 0079-6700
• DOI: 10.1016/j.progpolymsci.2023.101742

This review presents the state of the art of complex macromolecular architectures based on polylactide stereocomplexes (PLA-sc) from the viewpoint of synthesis and crystallization. First, we discuss the nomenclature, synthesis, epimerization, and lactide (LA) properties as a bio-derived cyclic dimeric monomer comprising two chiral carbons. Among several polymerization methods, catalytic ring-opening polymerization (ROP) is the most common and versatile technique to access stereoregular (isotactic) PLA, which is the prerequisite to preparing PLA-sc. Combined with other living and controlled/living polymerization techniques, ROP of LA has yielded various PLA-sc-based macromolecular architectures, including copolymers, stars, graft, cyclic, brush, and hybrid materials. New approaches to synthesizing monodisperse discrete oligoLA are also discussed. We show that a small change in the architectures, microstructures, molecular weight, or other chemical and physical modifications affects the behavior of PLA-sc. Moreover, the crystallization of PLA-sc, after more than 30 years of study, still presents many challenges. The crystalline morphology is also a subject of debate. Recent findings suggest a new crystalline unit cell for PLA-sc. Adding a third component or changing chain architecture can significantly modify the properties of the formed PLA-sc. The complex relationship between flexibility, nucleation, diffusion, and the interactions needed for the joint crystallization of the enantiomers constitutes a very large source of variables. As a result, PLA-based stereocomplex materials can be tailored by manipulating one or several of these variables. [Display omitted]