scholarly journals Facile Preparation of Stereoblock PLA From Ring-Opening Polymerization of rac-Lactide by a Synergetic Binary Catalytic System Containing Ureas and Alkoxides

2018 ◽  
Vol 6 ◽  
Author(s):  
Ze Kan ◽  
Wenlong Luo ◽  
Tong Shi ◽  
Chuanzhi Wei ◽  
Binghao Han ◽  
...  
Keyword(s):  
Catalytic System ◽  
Ring Opening ◽  
Ring Opening Polymerization ◽  
Facile Preparation

Sodium complexes bearing cavity-like conformations: a highly active and well-controlled catalytic system for macrolactone homo- and copolymerization

2021 ◽  
Vol 12 (13) ◽  
pp. 1957-1966
Author(s):  
Xinya Wang ◽  
Xiaohua Wang ◽  
Nuo Zhen ◽  
Jin Gu ◽  
Hao Zhang ◽  
...  
Keyword(s):  
Catalytic System ◽  
Ring Opening ◽  
Ring Opening Polymerization ◽  
Highly Active ◽  
Sodium Complexes

Sodium complexes displaying cavity-like conformations and, therefore, suppressed transesterification during the ring-opening polymerization of pentadecalactone are disclosed herein.

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 Chemoselective Ring-Opening Polymerization of Bio-Renewable α-Methylene-γ-Butyrolactone via an Organophosphazene/urea Binary Synergistic Catalytic System Toward a Sustainable Polyester

2020 ◽  
Author(s):  
Yong Shen ◽  
Wei Xiong ◽  
YongZheng Li ◽  
ZhiChao Zhao ◽  
Hua Lu ◽  
...  
Keyword(s):  
Double Bond ◽  
Catalytic System ◽  
Low Temperatures ◽  
Ring Opening ◽  
Theoretical Calculations ◽  
Unsaturated Polyester ◽  
Ring Opening Polymerization ◽  
Membered Ring ◽  
Exocyclic Double Bond ◽  
Binary Catalyst

Despite the great potential of bio-renewable a-methylene-<a></a><a></a><a>g-butyrolactone</a> (MBL) to produce functional recyclable polyester, the ring-opening polymerization (ROP) of MBL remains as a challenge due to the competing polymerization of the highly reactive exocyclic double bond and the low strained five membered ring. In this contribution, we present the first organocatalytic chemoselective ROP of MBL to exclusively produce recyclable unsaturated polyester by utilizing a phosphazene base/urea binary catalyst. We show that delicate chemoselectivity can be realized by controlling the temperature and using selected urea catalysts. Experimental and theoretical calculations provide mechanistic insights and indicate that the kinetically controlled ROP pathway is favored by using urea with stronger acidity at low temperatures.

A recyclable metal-free catalytic system for the cationic ring-opening polymerization of glycidol under ambient conditions

2021 ◽  
Author(s):  
Si Eun Kim ◽  
Hyun Ji Yang ◽  
Soonyoung Choi ◽  
Eunbyul Hwang ◽  
Minseong Kim ◽  
...  
Keyword(s):  
Catalytic System ◽  
Cationic Polymerization ◽  
Ring Opening ◽  
Environmentally Friendly ◽  
Ring Opening Polymerization ◽  
Ambient Conditions ◽  
Metal Free ◽  
Polymerization Condition ◽  
Polymer Topology ◽  
Cationic Ring Opening Polymerization

We developed a recyclable catalytic system for the metal-free cationic polymerization under ambient conditions, which provides mild and environmentally friendly polymerization condition as well as unique polymer topology.

Sign in / Sign up

Export Citation Format

Share Document