Preparation and Characterization of Poly (vinylbenzyl chloride)-b-poly (lactide) Copolymers via Nitroxide-Mediated Controlled Radical and Ring-Opening Polymerization

2012 ◽  
Vol 554-556 ◽  
pp. 295-298 ◽  
Author(s):  
Shao Hua Shen ◽  
Ying Xiang Duan ◽  
Qing Quan Liu ◽  
Qiu Guao Xiao
Keyword(s):  
Molecular Weight ◽  
Radical Polymerization ◽  
1H Nmr ◽  
Ring Opening ◽  
Ring Opening Polymerization ◽  
Controlled Radical Polymerization ◽  
Polydispersity Index ◽  
Molecular Weights ◽  
Lactide Copolymers

Hydroxyl-terminated poly(vinylbenzyl chloride) (PVBCOH) were synthesized using nitroxide-mediated controlled radical polymerization. Then, PVBCOH was used as a macro-initiator for ring-opening polymerization of lactide (LA) in the presence of stannous octanoate (Sn(Oct)2) as a catalyst. The structures, molecular weights and polydispersity index (PDI) of PVBCOH and PVBC-b-PLA were characterized by 1H-NMR, and GPC, respectively. The results indicated that PDI of PVBCOH and PVBC-b-PLA was 1.63 and 1.27, respectively. Moreover, the molecular weight and PDI of PVBCOH and PVBC-b-PLA could be well tuned by changing monomer-to-initiator ratio.

Synthesis of PCL-PS Star-Block Copolymer by Combination of Lipase-Catalyzed Ring-Opening Polymerization and ATRP

2006 ◽  
Vol 11-12 ◽  
pp. 749-752 ◽  
Author(s):  
Rui Xue Liu ◽  
Yan Shi ◽  
Zhi Feng Fu
Keyword(s):  
Block Copolymer ◽  
Block Copolymers ◽  
Atom Transfer Radical Polymerization ◽  
Radical Polymerization ◽  
1H Nmr ◽  
Ring Opening ◽  
Ring Opening Polymerization ◽  
Star Block Copolymer ◽  
Star Block Copolymers

Poly(ε-caprolactone) (PCL)-polystyrene (PS)star-block copolymer with a cross-linked microgel core were synthesized by the combination of atom transfer radical polymerization (ATRP) of St and lipase-catalyzed ring-opening polymerization (ROP) of ε-CL. The characterization of PCL-Br, PCL-PS-Br macroinitiator and PCL-PS Star-block copolymers was detected by GPC and 1H NMR. Results showed that the target star-block copolymers were successfully prepared.

Functionalized Polyesters via Stereoselective Electrochemical Ring-Opening Polymerization of O-Carboxyanhydrides

2020 ◽  
Author(s):  
Yongliang Zhong ◽  
quanyou feng ◽  
xiaoqian wang ◽  
jia chen ◽  
wenjun cai ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Glass Transition ◽  
Catalytic System ◽  
Ring Opening ◽  
Electrical Current ◽  
Ring Opening Polymerization ◽  
Glass Transition Temperatures ◽  
Molecular Weights ◽  
Molecular Weight Distributions ◽  
Weight Distributions

Ring-opening polymerization is used to prepare polyesters with precisely controlled molecular weights, molecular weight distributions, and tacticities. Herein, we report a newly developed Co/Zn catalytic system that can be activated by an electrical current to mediate efficient ring-opening polymerization of enantiopure <i>O</i>-carboxyanhydrides, allowing for the synthesis of isotactic functionalized polyesters with high molecular weights (>140 kDa) and narrow molecular weight distributions (<i>M</i><sub>w</sub>/<i>M</i><sub>n</sub> < 1.1). We also demonstrate that these catalysts can be used for stereoselective ring-opening polymerization of racemic <i>O</i>-carboxyanhydrides to synthesize syndiotactic or stereoblock copolymers with different glass transition temperatures compared with their atactic counterparts.

Synthesis and characterization of novel polysiloxane based ABA-type triblock copolymers using ATRP

e-Polymers ◽  
2013 ◽  
Vol 13 (1) ◽  
Author(s):  
Rajan B. Bodkhe ◽  
Dean C. Webster
Keyword(s):  
Radical Polymerization ◽  
Secondary Amine ◽  
Ring Opening ◽  
Triblock Copolymers ◽  
Gel Permeation Chromatography ◽  
Controlled Radical Polymerization ◽  
Synthesis And Characterization ◽  
Unique Material ◽  
Gel Permeation

Abstract Novel polysiloxane based ABA-type triblock copolymers having a secondary amine at the junction point were synthesized using a combination of ring opening equilibration polymerization (ROEP), Michael addition and atom transfer radical polymerization (ATRP). Polysiloxane based bifunctional ATRP macroinitiators were synthesized and subsequently used for controlled radical polymerization of t-butyl acrylate (t-BA) and sulfobetaine methacrylate (SBMA). Gel permeation chromatography (GPC) analysis of the triblocks based on t-BA showed high chain end functionality, due to the disappearance of peaks related to the macroinitiator. ROEP can be used to control the block length of the polysiloxane while ATRP can be used to control the chain length of the outer blocks, making the ABA- type triblock a unique material with secondary amine functionality which can be used for further reaction.

Chemical synthesis of novel biodegradable polyesters

1995 ◽  
Vol 41 (13) ◽  
pp. 282-288 ◽  
Author(s):  
Y. Hori ◽  
Y. Takahashi ◽  
A. Yamaguchi ◽  
T. Hagiwara
Keyword(s):  
Molecular Weight ◽  
Ring Opening ◽  
Lactone Ring ◽  
Ring Opening Polymerization ◽  
Optically Active ◽  
Bond Breaking ◽  
Carbonyl Carbon ◽  
Biodegradable Polyesters ◽  
Molecular Weights ◽  
High Molecular Weight Poly

Distannoxane complexes catalyze the ring-opening polymerization of optically active β-butyrolactone (β-BL) to afford a high molecular weight poly(3-hydroxybutyrate). When 1-ethoxy-3-chlorotetrabutyldistannoxane was used as a catalyst (catalyst/(R)-β-BL = 1/8000 at 100 °C for 4 h), poly((R)-3-hydroxybutyrate) was obtained from (R)-β-BL in a yield of 99%. The copolymerizations of (R)-β-BL with racemic β-BL in several ratios gave corresponding stereocopolymers. The copolymerizations of (R)-β-BL with ε-caprolactone, δ-valerolactone, β-methyl-δ-valerolactone, and L-lactide afforded novel optically active and biodegradable polyesters of high molecular weights, comprising (R)-3-hydroxybutyrate (3HB). The polymerization of (R)-β-BL catalyzed by the distannoxane complexes proceeded by bond breaking between the carbonyl carbon and oxygen atom of the lactone ring (acyl cleavage) with retention of the configuration and little or no racemization. Polymers that have over 80 mol% of the (R)-3HB unit were found to have almost the same degree of biodegradability as the copolyester of 3-hydroxybutyrate and 11% 3-hydroxyvalerate produced by the microbial method.Key words: distannoxane, ring-opening polymerization, poly(3-hydroxybutyrate), poly(3-hydroxyalkanoates), biodegradable polymer.

Synthesis and Characterization of a Novel Star-Shaped Polymers with Biological Compatibility via Ring-Opening Polymerization and Atom Transfer Radical Polymerization

2012 ◽  
Vol 602-604 ◽  
pp. 727-731
Author(s):  
Shi Biao Zhou ◽  
An Guo Xiao ◽  
Yuan Dao Chen ◽  
Yong Bing Zhuan ◽  
Yun Wang
Keyword(s):  
Atom Transfer Radical Polymerization ◽  
Radical Polymerization ◽  
Ring Opening ◽  
Ring Opening Polymerization ◽  
Polymer Structure ◽  
Atom Transfer ◽  
Hyperbranched Polyester ◽  
Biological Compatibility ◽  
Star Shaped Polymer

Hydroxyl functional hyperbranched polyester initiators initiated the ring-opening polymerization(ROP) of ε-caprolactone (CL) and the star-shaped polymer with PCL arms using hyperbranched polyester as nuclear was produced. Then, the bromide of star-shaped polymer, initiated the atom transfer radical polymerization (ATRP) of oligo(ethylene oxide) methacrylate (OEOMA) and the star-shaped polymer containing the arms of PCL-b-POEOMA was synthesized ,and the characterization of polymer structure was investigated by NMR.

scholarly journals Functionalized Polyesters via Stereoselective Electrochemical Ring-Opening Polymerization of O-Carboxyanhydrides

2020 ◽  
Author(s):  
Yongliang Zhong ◽  
quanyou feng ◽  
xiaoqian wang ◽  
jia chen ◽  
wenjun cai ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Glass Transition ◽  
Catalytic System ◽  
Ring Opening ◽  
Electrical Current ◽  
Ring Opening Polymerization ◽  
Glass Transition Temperatures ◽  
Molecular Weights ◽  
Molecular Weight Distributions ◽  
Weight Distributions

Ring-opening polymerization is used to prepare polyesters with precisely controlled molecular weights, molecular weight distributions, and tacticities. Herein, we report a newly developed Co/Zn catalytic system that can be activated by an electrical current to mediate efficient ring-opening polymerization of enantiopure <i>O</i>-carboxyanhydrides, allowing for the synthesis of isotactic functionalized polyesters with high molecular weights (>140 kDa) and narrow molecular weight distributions (<i>M</i><sub>w</sub>/<i>M</i><sub>n</sub> < 1.1). We also demonstrate that these catalysts can be used for stereoselective ring-opening polymerization of racemic <i>O</i>-carboxyanhydrides to synthesize syndiotactic or stereoblock copolymers with different glass transition temperatures compared with their atactic counterparts.

scholarly journals Photocatalyst-Independent Photoredox Ring-Opening Polymerization of O-Carboxyanhydrides: Stereocontrol and Mechanism

2021 ◽  
Author(s):  
Yongliang Zhong ◽  
quanyou feng ◽  
xiaoqian wang ◽  
Lei Yang ◽  
Rong Tong
Keyword(s):  
Molecular Weight ◽  
Ring Opening ◽  
Precious Metal ◽  
Ring Opening Polymerization ◽  
Oxidative Status ◽  
Mechanistic Studies ◽  
Glass Transition Temperatures ◽  
Molecular Weights ◽  
Molecular Weight Distributions ◽  
Weight Distributions

Photoredox ring-opening polymerization of <i>O</i>-carboxyanhydrides allows for the synthesis of polyesters with precisely controlled molecular weights, molecular weight distributions, and tacticities. While powerful, obviating the use of precious metal-based photocatalysts would be attractive from the perspective of simplifying the protocol and enabling unexpected reactivity. Herein, we report the Co and Zn catalysts that are activated by external light to mediate efficient ring-opening polymerization of <i>O</i>-carboxyanhydrides, without the use of exogenous precious metal-based photocatalysts. Our methods allow for the synthesis of isotactic polyesters with high molecular weights (>200 kDa) and narrow molecular weight distributions (<i>M</i><sub>w</sub>/<i>M</i><sub>n</sub> < 1.1). Mechanistic studies indicate that light activates the oxidative status of Co<sup>III</sup> intermediate that is generated from the regioselective ring-opening of the <i>O</i>-carboxyanhydride. We also demonstrate that the use of Zn or Hf complexes together with Co can allow for stereoselective photoredox ring-opening polymerizations of multiple racemic <i>O</i>-carboxyanhydrides to synthesize syndiotactic and stereoblock copolymers, which vary widely in their glass transition temperatures.

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