Microwave-Assisted Synthesis of Poly(L -lactic acid) via Direct Melt Polycondensation Using Solid Super-Acids

2009 ◽  
Vol 210 (23) ◽  
pp. 2058-2062 ◽  
Author(s):  
Hai Lei Cao ◽  
Peng Wang ◽  
Wei Bo Yuan
Keyword(s):  
Lactic Acid ◽  
Microwave Assisted Synthesis ◽  
Microwave Assisted ◽  
Melt Polycondensation ◽  
Direct Melt Polycondensation

Research on the Modification of Poly(L-Lactic Acid) by Glucose via Direct Melt Polycondensation

2011 ◽  
Vol 311-313 ◽  
pp. 1106-1109 ◽  
Author(s):  
Shi He Luo ◽  
Shi Qin Yu ◽  
Jian Xiao Li ◽  
Zhao Yang Wang
Keyword(s):  
Drug Delivery ◽  
Lactic Acid ◽  
Feed Ratio ◽  
Biodegradable Material ◽  
Drug Delivery Application ◽  
H Nmr ◽  
Melt Polycondensation ◽  
Molar Feed Ratio ◽  
Direct Melt Polycondensation

Directly using L-lactic acid (L-LA) and glucose (Glu) as the starting materials, novel biodegradable material poly(L-lactic acid-co-glucose) [P(L-LA-co-Glu)] was synthesized via direct melt polycondensation. The copolymers P(L-LA-co-Glu)s at different molar feed ratios were characterized by FTIR,1H-NMR, GPC, DSC and XRD. All poly(L-lactic acid) modified by Glu was partly crystalline. And their Mw, Tm, and crystallinity basically increased with the increase of the molar feed ratio n(L-LA) : n(Glu). When n(Glu) : n(L-LA) was 1 : 750, the biggest Mw was 5900 Da, and all Mwcould meet the requirement for drug delivery application.

Synthesis of Star-Shaped PLA via Direct Melt Polycondensation: 1. Using L-LA as Starting Material

2010 ◽  
Vol 152-153 ◽  
pp. 1236-1239
Author(s):  
Zhao Yang Wang ◽  
Chao Xu Mao ◽  
Yu Fen Luo ◽  
Shi He Luo ◽  
Jun Min Nan
Keyword(s):  
Drug Delivery ◽  
Lactic Acid ◽  
Low Cost ◽  
Starting Material ◽  
Feed Ratio ◽  
Simple Process ◽  
The Core ◽  
Melt Polycondensation ◽  
Molar Feed Ratio ◽  
Direct Melt Polycondensation

Using 1,3,5-benzenetrioxyundecanol (mTU) as the core, and L-lactic acid (L-LA) as starting material, a novel star-shaped poly(L-lactic acid) (SPLLA) was synthesized via direct melt polycondensation with simple process and low-cost. The obtained biodegradable polymer SPLLA was systematically characterized with the intrinsic viscosity [η], FTIR, 1H-NMR, GPC and XRD. The Mw, Tg, Tm, ΔH, crystallinity, crystallite size of all SPLLA basically increased with the increase of the molar feed ratio n(L-LA) : n(mTU). When n(L-LA) : n(mTU) was 500:1, the biggest Mw was 8600, but all Mw meet the requirement for drug delivery application.

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.

Synthesis of a Biodegradable Material Poly(lactic acid-co-melamine) via Direct Melt Polycondensation

2013 ◽  
Vol 781-784 ◽  
pp. 503-506
Author(s):  
Min Hua Feng ◽  
Jin Feng Xiong ◽  
Qun Fang Wang ◽  
Zhao Yang Wang
Keyword(s):  
Lactic Acid ◽  
Flame Retardant ◽  
Stannous Chloride ◽  
Feed Ratio ◽  
Poly Lactic Acid ◽  
Biodegradable Material ◽  
Melt Polycondensation ◽  
Melt Copolymerization ◽  
Molar Feed Ratio ◽  
Direct Melt Polycondensation

Directly starting fromD,L-lactic acid (LA) and melamine (MA), novel star-shaped biodegradable material poly (lactic acid-co-melamine) [P(LA-co-MA)] as a kind of potential flame retardant is synthesized via melt polycondensation. When the molar feed ration(LA)/n(MA) is 60/1, the optimal synthetic conditions are discussed. After the prepolymerization at 140 °C for 8 h, using 0.4wt% stannous chloride as the catalyst, the melt copolymerization at 160 °C for 8 h gives the copolymer with the biggest intrinsic viscosity 0.87 dLg-1.

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