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.

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.

Reaction Mechanism on the Modification of PLA by Melamine via DMP

2013 ◽  
Vol 781-784 ◽  
pp. 495-498
Author(s):  
Qun Fang Wang ◽  
Jin Feng Xiong ◽  
Ming Li Zhong ◽  
Zhao Yang Wang
Keyword(s):  
Lactic Acid ◽  
Functional Groups ◽  
Core Structure ◽  
Feed Ratio ◽  
Poly Lactic Acid ◽  
Internal Factors ◽  
Melt Polycondensation ◽  
Molar Feed Ratio ◽  
Direct Melt Polycondensation ◽  
Peak Value

When poly (lactic acid-co-melamine) [P(LA-co-MA)] is synthesized via direct melt polycondensation (DMP), with the more MA in the feed content, the copolymer with a three-MA-core structure linked by the ether bond is formed. Increasing the molar feed ration(LA)/n(MA), the structure of the copolymers is gradually changed from multi-core structure into SPLA structure only containing one MA core, and a peak value of Mwexists as expected. The aromatic cores with different functional groups have an important influence on the Mwpeak value, and the internal factors are the conjugate effect and the nucleophilicity caused by the different functional groups themselves.

Synthesis of Poly(D,L-Lactic Acid-Co-Glucose) via Direct Polycondensation and its Characterization

2011 ◽  
Vol 80-81 ◽  
pp. 370-374 ◽  
Author(s):  
Shi He Luo ◽  
Zhao Yang Wang ◽  
Dong Na Huang ◽  
Chao Xu Mao ◽  
Jin Feng Xiong
Keyword(s):  
Drug Delivery ◽  
Lactic Acid ◽  
Polylactic Acid ◽  
1H Nmr ◽  
Biodegradable Material ◽  
Direct Polycondensation ◽  
Carrier Material ◽  
Melt Polymerization ◽  
Drug Delivery Carrier ◽  
Melt Polycondensation

Directly using cheap D,L-lactic acid (D,L-LA) and glucose (Glu) as starting materials, biodegradable material poly(D,L-lactic acid-co-Glucose) [P(D,L-LA-co-Glu)] was synthesized via melt polycondensation. When n(Glu) : n(D,L-LA) = 1:200, the appropriate synthetic condition is that: after 120 °C prepolymerization for 5 h, 160 °C melt polymerization catalyzed by w(SnCl2) = 0.5% for 5 h. P(D,L-LA-co-Glu) with different molar feed ratios were synthesized and characterized with [η], FTIR, 1H NMR, GPC and XRD. The Tg of all copolymer P(D,L-LA-co-Glu) was lower than that of homopolymer polylactic acid directly synthesized via melt polycondensation. The copolymers with Mw from 2,100 Da to 5,100 Da could meet the demand of drug delivery carrier material.

Synthesis of Star-Shaped PLA via Direct Melt Polycondensation: 2. Using D,L-LA as Starting Material

2010 ◽  
Vol 152-153 ◽  
pp. 1301-1304
Author(s):  
Zhao Yang Wang ◽  
Wen Kun Hong ◽  
Yu Fen Luo ◽  
Qun Fang Wang ◽  
Xin Xiao
Keyword(s):  
Drug Delivery ◽  
Lactic Acid ◽  
Biodegradable Polymer ◽  
Low Cost ◽  
Starting Material ◽  
Simple Process ◽  
The Core ◽  
Melt Polycondensation ◽  
Direct Melt Polycondensation ◽  
Linear Poly

Using 1,3,5-benzenetrioxyundecanol (mTU) as the core, and more cheaper D,L-lactic acid (D,L-LA) as starting material, a novel star-shaped poly(D,L-lactic acid) (SPDLLA) was synthesized via direct melt polycondensation with simple process and low-cost. The obtained biodegradable polymer SPDLLA was systematically characterized with the intrinsic viscosity [η], FTIR, 1H-NMR, GPC and XRD. The Tg and crystallinity of all SPDLLA were much lower than that of the linear poly(D,L-lactic acid). When n(D,L-LA) : n(mTU) was 120 : 1, the biggest Mw was 10800, which was bigger than that obtained from L-lactic acid (L-LA). All Mw meet the requirement for drug delivery application.

Melt Polycondensation and Analysis of Hydroxyl-Terminated Poly(L-lactic Acid) Using Small Molecular Diols as Terminating Agents

2013 ◽  
Vol 328 ◽  
pp. 890-894
Author(s):  
Jing Che ◽  
Rong Jie Yang
Keyword(s):  
Lactic Acid ◽  
Ethylene Glycol ◽  
Gel Permeation Chromatography ◽  
Catalyst System ◽  
Molecular Weights ◽  
H Nmr ◽  
Melt Polycondensation ◽  
Direct Melt Polycondensation ◽  
Group Structures ◽  
End Group

The synthesis of hydroxyl-terminated poly (L-lactic acid) (PLLA) by direct melt polycondensation of L-lactic acid and use of small molecular diols as terminating agents was investigated. L-lactic acid was dewatered to prepare the dehydrated prepolymer at first. Then PLLA was prepared through melt polycondensation in a melt with catalyst system including TSA, SnCl2and Sn (Oct)2. Finally, ethylene glycol, 1,4-butanediol, and 1,8-octanediol, respectively, were used in hydroxyl termination of the PLLA. The molecular weights and end-group structures of all products were characterized by gel permeation chromatography (GPC) and1H-NMR. DSC and Disc Polarimeter were used to characterize crystallinity and racemization, respectively. The results show that two kinds of hydroxyl-terminated PLLA polymers were obtained: complete hydroxyl-terminated PLLA prepared by using ethylene glycol or 1,4-butanediol, incomplete hydroxyl-terminated PLLA prepared by using 1,8-octanediol or combination of two kinds of diols. Combination of ethylene glycol or 1,4-butanediol with 1,8-octanediol can reach high hydroxyl termination of PLLA, and maintain the molecular weight by decrease of alcoholysis at the same time.1H-NMR was found as an effective estimating way for extents of reactions. The hydroxyl-terminating reactions of PLLA by the diols reduced the crystallinity and resulted in racemization to some extent.

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