Green Copolymers Based on Poly(Lactic Acid)—Short Review

Abstract

Polylactic acid (PLA) is a biodegradable and biocompatible polymer that can be applied in the field of packaging and medicine. Its starting substrate is lactic acid and, on this account, PLA can also be considered an ecological material produced from renewable resources. Apart from several advantages, polylactic acid has drawbacks such as brittleness and relatively high glass transition and melting temperatures. However, copolymerization of PLA with other polymers improves PLA features, and a desirable material marked by preferable physical properties can be obtained. Presenting a detailed overview of the accounts on the PLA copolymerization accomplishments is the innovation of this paper. Scientific findings, examples of copolymers (including branched, star, grafted or block macromolecules), and its applications are discussed. As PLA copolymers can be potentially used in pharmaceutical and biomedical areas, the attention of this article is also placed on the advances present in this field of study. Moreover, the subject of PLA synthesis is described. Three methods are given: azeotropic dehydrative condensation, direct poly-condensation, and ring-opening polymerization (ROP), along with its mechanisms. The applied catalyst also has an impact on the end product and should be adequately selected depending on the intended use of the synthesized PLA. Different ways of using stannous octoate (Sn(Oct)2) and examples of the other inorganic and organic catalysts used in PLA synthesis are presented.

Physico-Chemical Characteristics and Posterolateral Fusion Performance of Biphasic Calcium Phosphate with Submicron Needle-Shaped Surface Topography Combined with a Novel Polymer Binder

“…The lack of adverse reaction based on local and systemic histological observations further confirms the safe use of the stannous octoate catalyst, one of the most widely known and used catalysts for PLA polymerization, which is approved by the FDA for human use and commonly used for other approved bone contacting devices [47].…”

Poly(Lactic Acid)-Based Microparticles for Drug Delivery Applications: An Overview of Recent Advances

“…PLA's high hydrophobicity makes it an excellent biomaterial for such applications, while poly(ethylene glycol) (PEG) is a biocompatible hydrophilic polymer used extensively in many applications in pharmaceutical technology. Such poly(L-lactide)/poly(ethylene glycol) (PLLA/PEG) copolymers can be easily prepared by ring opening polymerization of lactide in the presence of PEG and a catalyst, usually stannous octoate [93]. Hydroxyl end groups can act as initiators for lactide polymerization, and according to this procedure diblock or triblock copolymers can be prepared.…”

Green Chemistry and Molecularly Imprinted Membranes

“…One of the different goals pursued in the field of materials science is the application of GC for producing sustainable green polymers and membranes [ 62 , 63 , 64 , 65 , 66 , 67 , 68 , 69 , 70 , 71 , 72 , 73 , 74 , 75 ] as well as inorganic–organic hybrid materials of based on a polymeric matrix holding a small amount of inorganic material (such as carbon-based nanotubes, metal nanoparticles and graphene oxide) [ 76 , 77 , 78 , 79 , 80 , 81 ]. Green chemistry has been applied for fabricating numerous biopolymers, biopolymer-based membranes [ 64 , 66 ] and different synthetic polymers, such as acrylic-based polymers [ 82 ], poly(vinyl) chloride [ 83 ], polyurethane [ 84 ], and so on. Synthetic processes include the use of biomass-based sources [ 85 ] and renewable raw monomers such as triglycerides, terpenes, allylic and olefinic monomers [ 85 , 86 ].…”