Recent Progress in Using Stereocomplexation for Enhancement of Thermal and Mechanical Property of Polylactide

Abstract

Polylactide (PLA) has been receiving significant attention in biopolymer research due to its excellent biodegradability, biocompatibility and sustainability. The mass production of PLA from renewable agricultural resources has delved this green material as a top alternative to replace the petroleum-based conventional polymers. However, the inherent weaknesses of PLA in its raw state such as brittleness, low heat distortion temperature and recrystallization rate, as well as the inadequate crystallization ability and degree after fast processing have limited the competitive edge of PLA over traditional synthetic plastics in industrial use or for biomedical applications. Being different from other types of biodegradable polymers, the diverse isomeric forms of PLA have provided great opportunities for thermal and mechanical enhancement through stereocomplexation formation. In this review, we present the most recent development in thermal and mechanical enhancement of PLA via stereocomplexation of PLA in different polymeric systems, including enantiomeric PLA homopolymers, PLA-based block and graft copolymers, as well as enantiomeric PLA materials having unique architectures such as cyclic, star, dendritic and comb-shaped. Insightful discussion on the influence of crystal structure and intermolecular interactions between PLLA and PDLA in the different polymeric systems on the enhanced performance of the resultant materials are provided. The enhanced PLA with diverse functions oriented toward engineering materials and their biosignificance in different areas are also covered in this review.

Nano‐Star‐Shaped Polymers for Drug Delivery Applications

“…Also, as water is present in huge amounts in the body, hydrolysis is typically looked at as one of the ways to degrade the arms, and this explains why polyester‐based structures are typically utilized in the arms of CCS polymers. For instance, similar to PLA, PCL is also generally considered to be a biocompatible and biodegradable (although it takes some time) polymer and this is incorporated into the arms of star‐shaped polymers by using alkyl halide functionalized PCL chains in the synthesis process. These are then cross‐linked to the core with monomeric divinyl species such as DVB so that the arms can be easily removed by hydrolysis, without disturbing the functionality of the star's core ( Figure ) .…”

Relationship between the crystallization behavior of poly(ethylene glycol) and stereocomplex crystallization of poly(L‐lactic acid)/poly(D‐lactic acid)

“…Therefore, research of SCs of PLLA/poly( d ‐lactic acid) (PDLA) has attracted much attention . Li and co‐workers published excellent review articles on the recent progress in utilizing SC formation strategy to enhance the thermal and mechanical properties of PLA. Chen and co‐workers have devoted themselves to the research of PLA and SCs for many years .…”

Fully bio-based, highly toughened and heat-resistant poly(L-lactide) ternary blends via dynamic vulcanization with poly(D-lactide) and unsaturated bioelastomer

“…With attractive sustainability, biocompatibility, biodegradability, and mechanical strength, poly(L-lactide) (PLLA) is considered a promising alternative to petroleum-based polymers. However, its wide applications have been obstructed by the inherent brittleness and low heat resistance, as evidenced by the poor impact resistance and tensile toughness as well as low heat distortion temperature (HDT) [3][4][5][6]. Therefore, many efforts have been made to improve the toughness and heat resistance of PLLA for expansion of its applications [7][8][9][10][11].…”

“…In addition, incorporation of PDLA would change the rheological behavior of PLLA and facilitate morphology regulation of PLLA-based blends [44,45]. Therefore, SC crystallites have attracted increasing attention in recent years [3,4,46].…”