scholarly journals An organocatalytic ring-opening polymerization approach to highly alternating copolymers of lactic acid and glycolic acid

2020 ◽  
Vol 11 (39) ◽  
pp. 6365-6373
Author(s):  
Kaoru Takojima ◽  
Hiroshi Makino ◽  
Tatsuya Saito ◽  
Takuya Yamamoto ◽  
Kenji Tajima ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Ring Opening ◽  
Glycolic Acid ◽  
Ring Opening Polymerization ◽  
Optically Active ◽  
Alternating Copolymers ◽  
Alternating Copolymer ◽  
Alcohol System

Highly regioselective ring-opening polymerization of optically active methylglycolides was achived using P2-t-Bu/alcohol system to produce alternating copolymer of lactic acid and glycolic acid.

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

Highly Regioselective Ring-Opening Polymerization of Cyclic Diester for Alternating Sequence-Controlled Copolymer Synthesis of Mandelic Acid and Glycolic Acid

2019 ◽  
Vol 52 (20) ◽  
pp. 7564-7571 ◽  
Author(s):  
Yaru Wang ◽  
Zhaowei Jia ◽  
Jinxing Jiang ◽  
Xiaoyang Mao ◽  
Xiaobo Pan ◽  
...  
Keyword(s):  
Ring Opening ◽  
Mandelic Acid ◽  
Glycolic Acid ◽  
Ring Opening Polymerization

Cationic Ring-Opening Polymerization of Optically Active N-Substituted Cyclic Thiourethanes

2004 ◽  
Vol 37 (20) ◽  
pp. 7538-7542 ◽  
Author(s):  
Atsushi Nagai ◽  
Bungo Ochiai ◽  
Takeshi Endo
Keyword(s):  
Ring Opening ◽  
Ring Opening Polymerization ◽  
Optically Active ◽  
Cationic Ring Opening Polymerization

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

scholarly journals Ring-Opening Polymerization of l-Lactic Acid O-Carboxyanhydrides Initiated by Alkoxy Rare Earth Compounds

Molecules ◽  
2013 ◽  
Vol 18 (10) ◽  
pp. 12768-12776 ◽  
Author(s):  
Zhengguo He ◽  
Lin Jiang ◽  
Yongming Chuan ◽  
Hongli Li ◽  
Minglong Yuan
Keyword(s):  
Lactic Acid ◽  
Rare Earth ◽  
Ring Opening ◽  
Ring Opening Polymerization ◽  
Rare Earth Compounds
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