High pressure water-initiated ring opening polymerization for the synthesis of well-defined α-hydroxy-ω-(carboxylic acid) polycaprolactones

2017 ◽  
Vol 19 (15) ◽  
pp. 3618-3627 ◽  
Author(s):  
A. Dzienia ◽  
P. Maksym ◽  
M. Tarnacka ◽  
I. Grudzka-Flak ◽  
S. Golba ◽  
...  
Keyword(s):  
Molecular Weight ◽  
High Pressure ◽  
Carboxylic Acid ◽  
Ring Opening ◽  
Chemical Structure ◽  
Ring Opening Polymerization ◽  
Molecular Weight Distributions ◽  
Weight Distributions ◽  
Pressure Water ◽  
Novel Method

A novel method to produce polyesters of a well-defined chemical structure, and narrow molecular weight distributions by using a combination of high pressure, temperature and water was proposed.

Sn(OTf)2 catalyzed continuous flow ring-opening polymerization of ε-caprolactone

RSC Advances ◽  
2015 ◽  
Vol 5 (40) ◽  
pp. 31554-31557 ◽  
Author(s):  
Ning Zhu ◽  
Zilong Zhang ◽  
Weiyang Feng ◽  
Yuqiang Zeng ◽  
Zhongyue Li ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Continuous Flow ◽  
Ring Opening ◽  
Ring Opening Polymerization ◽  
Reaction Conditions ◽  
Molecular Weight Distributions ◽  
Weight Distributions

A simple PTFE tubular microreactor based platform was successfully developed to conduct Sn(OTf)2 catalyzed ε-caprolactone polymerization with better control of reaction conditions, faster polymerizations and narrower molecular weight distributions.

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 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.

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 ◽  
Andrew G. Korovich ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Ring Opening ◽  
Ring Opening Polymerization ◽  
Molecular Weights ◽  
Molecular Weight Distributions ◽  
Weight Distributions

Photoredox ring-opening polymerization of O-carboxyanhydrides allows for the synthesis of functionalized polyesters with high molecular weights, narrow molecular weight distributions, and various tacticities.

scholarly journals Synthesis of poly(disulfide)s with narrow molecular weight distributions via lactone ring-opening polymerization

2020 ◽  
Vol 11 (19) ◽  
pp. 4882-4886
Author(s):  
Sungwhan Kim ◽  
Kamila I. Wittek ◽  
Yan Lee
Keyword(s):  
Molecular Weight ◽  
Ring Opening ◽  
Lactone Ring ◽  
Ring Opening Polymerization ◽  
Controlled Polymerization ◽  
Molecular Weight Distributions ◽  
Weight Distributions

We report the first example of controlled polymerization of poly(disulfide)s with narrow molecular weight distributions.

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.

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

2020 ◽  
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.

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

2020 ◽  
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.

The Use of Novel F-RAFT Agents in High Temperature and High Pressure Ethene Polymerization: Can Control be Achieved?

2007 ◽  
Vol 60 (10) ◽  
pp. 788 ◽  
Author(s):  
Markus Busch ◽  
Marion Roth ◽  
Martina H. Stenzel ◽  
Thomas P. Davis ◽  
Christopher Barner-Kowollik
Keyword(s):  
Molecular Weight ◽  
High Pressure ◽  
High Temperature ◽  
Degree Of Polymerization ◽  
Molecular Weight Distributions ◽  
High Pressure High Temperature ◽  
Reversible Addition ◽  
Weight Distributions ◽  
Raft Agent ◽  
Initial Results

Simulations are employed to establish the feasibility of achieving controlled/living ethene polymerizations. Such simulations indicate that reversible addition–fragmentation chain transfer (RAFT) agents carrying a fluorine Z group may be suitable to establish control in high-pressure high-temperature ethene polymerizations. Based on these simulations, specific fluorine (F-RAFT) agents have been designed and tested. The initial results are promising and indicate that it may indeed be possible to achieve molecular weight distributions with a polydispersity being significantly lower than that observed in the conventional free radical process. In our initial trials presented here (using the F-RAFT agent isopropylfluorodithioformate), a correlation between the degree of polymerization and conversion can indeed be observed. Both the lowered polydispersity and the linear correlation between molecular weight and conversion indicate that control may in principle be possible.

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