Synthesis and synthetic mechanism of Polylactic acid

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Xavier Montané ◽  
Josep M. Montornes ◽  
Adrianna Nogalska ◽  
Magdalena Olkiewicz ◽  
Marta Giamberini ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Polylactic Acid ◽  
Ring Opening ◽  
Fossil Fuel ◽  
Raw Materials ◽  
Ring Opening Polymerization ◽  
Bifunctional Catalysts ◽  
Organometallic Catalysts ◽  
Polymer Properties ◽  
Organic Catalyst

AbstractAt present, Polylactic acid (PLA) is one of the most used biodegradable polyesters. The good properties and its biodegradability make that PLA can replace the fossil fuel derived polymers in different applications. PLA can be synthesized by using different methodologies. Among them, the most widely used forms on an industrial scale are the direct polycondensation of Lactic acid and the ring-opening polymerization of cyclic Lactide. The final properties of the obtained PLA are dependent on the used stereoisomers of the raw materials (Lactic acid and/or Lactide) and the conditions employed to polymerize them. Therefore, the comprehension of the synthetic mechanism of PLA is crucial to control the stereoregularity of PLA, which in turn results in an improvement of the polymer properties. So, distinct mechanisms for the synthesis of PLA by ring-opening polymerization using different catalysts systems (organometallic catalysts, cationic catalyst, organic catalyst, bifunctional catalysts) are examined in this review.

Microwave-assisted ring-opening polymerization of poly (glycolic acid-co-lactic acid) copolymers

e-Polymers ◽  
2010 ◽  
Vol 10 (1) ◽  
Author(s):  
Guang Li ◽  
Na Zhao ◽  
Wei Bai ◽  
Dong Liang Chen ◽  
Cheng Dong Xiong
Keyword(s):  
Lactic Acid ◽  
Ring Opening ◽  
Glycolic Acid ◽  
Raw Materials ◽  
Irradiation Time ◽  
Ring Opening Polymerization ◽  
Feed Ratio ◽  
Microwave Assisted Synthesis ◽  
Component Ratio ◽  
Microwave Assisted

AbstractThe microwave-assisted synthesis of poly(glycolic acid-co-lactic acid) (PGLA) copolymers by ring-opening polymerization of glycolide (GA) and L-lactide (L-LA) was studied. The microwave irradiation time and feed ratios on the molecular weights, as well as the thermal properties of the copolymers were discussed. These copolymers were characterized by 1H-NMR, GPC and DSC. It was found that the largest molecular weight ([η]: 0.8745 dL/g) of PGLA5050 was obtained at the irradiation time of 5 min. The color of the copolymers changed from white to light brown, and the yield was higher with the extension of the irradiation time. The molar component ratio of GA in PGLA (FG) was higher than the initial GA feed ratio (nGA) in the raw materials. As the nGA content increased, the glass transition temperature (Tg) of the copolymers decreased and the melting temperature (Tm) of the copolymers increased.

scholarly journals Synthesis and Characterization of Polyphosphazenes Modified with Hydroxyethyl Methacrylate and Lactic Acid

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Evelyn Carolina Martínez Ceballos ◽  
Ricardo Vera Graziano ◽  
Gonzalo Martínez Barrera ◽  
Oscar Olea Mejía
Keyword(s):  
Lactic Acid ◽  
Ring Opening ◽  
Room Temperature ◽  
Block Structure ◽  
Ring Opening Polymerization ◽  
Synthesis And Characterization ◽  
Poly Lactic Acid ◽  
Hydroxyethyl Methacrylate ◽  
H Nmr

Poly(dichlorophosphazene) was prepared by melt ring-opening polymerization of the hexachlorocyclotriphosphazene. Poly[bis(2-hydroxyethyl-methacrylate)-phosphazene] and poly[(2-hydroxyethyl-methacrylate)-graft-poly(lactic-acid)-phosphazene] were obtained by nucleophilic condensation reactions at different concentrations of the substituents. The properties of the synthesized copolymers were assessed by FTIR,1H-NMR and31P-NMR, thermal analysis (DSC-TGA), and electron microscopy (SEM). The copolymers have a block structure and show twoTg's below room temperature. They are stable up to a temperature of 100°C. The type of the substituents attached to the PZ backbone determines the morphology of the polymers.

scholarly journals Development of Four Unit Processes for Biobased PLA Manufacturing

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Chae Hwan Hong ◽  
Si Hwan Kim ◽  
Ji-Yeon Seo ◽  
Do Suck Han
Keyword(s):  
Lactic Acid ◽  
Ring Opening ◽  
Lactic Acid Production ◽  
Scale Up ◽  
Catalyst System ◽  
Ring Opening Polymerization ◽  
Acid Fermentation ◽  
Manufacturing Method ◽  
Renewable Biomass ◽  
Microbial Productivity

Polylactide (PLA), which is one of the most important biocompatible polyesters that are derived from annually renewable biomass such as corn and sugar beets, has attracted much attention for automotive parts application. The manufacturing method of PLA is the ring-opening polymerization of the dimeric cyclic ester of lactic acid, lactide. For the stereocomplex PLA, we developed the four unit processes, fermentation, separation, lactide conversion, and polymerization. Fermentation of sugars to D-lactic acid is little studied, and its microbial productivity is not well known. Therefore, we investigated D-lactic acid fermentation with a view to obtaining the strains capable of producing D-lactic acid, and we got a maximum lactic acid production 60 g/L. Lactide is prepared by a two-step process: first, the lactic acid is converted into oligo(lactic acid) by a polycondensation reaction; second, the oligo(lactic acid) is thermally depolymerized to form the cyclic lactide via an unzipping mechanism. Through catalyst screening test for polycondensation and depolymerization reactions, we got a new method which shortens the whole reaction time 50% the level of the conventional method. Poly(L-lactide) was obtained from the ring-opening polymerization of L-lactide. We investigated various catalysts and polymerization conditions. Finally, we got the best catalyst system and the scale-up technology.

scholarly journals Elucidating a Unified Mechanistic Scheme for the DBU-Catalyzed Ring-Opening Polymerization of Lactide to Poly(lactic acid)

2016 ◽  
Vol 49 (13) ◽  
pp. 4699-4713 ◽  
Author(s):  
Nicholas J. Sherck ◽  
Hyun Chang Kim ◽  
You-Yeon Won
Keyword(s):  
Lactic Acid ◽  
Ring Opening ◽  
Ring Opening Polymerization ◽  
Poly Lactic Acid

Construction of polyphosphoesters with the main chain of rigid backbones and stereostructures via organocatalyzed ring-opening polymerization

2020 ◽  
Vol 11 (20) ◽  
pp. 3475-3480
Author(s):  
Yu-Jia Zheng ◽  
Guan-Wen Yang ◽  
Bo Li ◽  
Guang-Peng Wu
Keyword(s):  
Ring Opening ◽  
Main Chain ◽  
Catalyst System ◽  
Ring Opening Polymerization ◽  
System P ◽  
Organic Catalyst

A highly stereoregular polyphosphoester with a rigid cyclohexylene structure in the main chain was constructed via ring-opening polymerization (ROP) in the presence of an organic catalyst system.

Surface-Modified Cellulose Nanofibers-graft-poly(lactic acid)s Made by Ring-Opening Polymerization of l-Lactide

2019 ◽  
Vol 27 (4) ◽  
pp. 847-861 ◽  
Author(s):  
Chaniga Chuensangjun ◽  
Kyohei Kanomata ◽  
Takuya Kitaoka ◽  
Yusuf Chisti ◽  
Sarote Sirisansaneeyakul
Keyword(s):  
Lactic Acid ◽  
Ring Opening ◽  
Cellulose Nanofibers ◽  
Ring Opening Polymerization ◽  
Poly Lactic Acid ◽  
Surface Modified ◽  
Modified Cellulose
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