Immortal ring-opening polymerization of ε-caprolactone by a neat magnesium catalyst system: an approach to obtain block and amphiphilic star polymers in situ

2014 ◽  
Vol 5 (15) ◽  
pp. 4580-4588 ◽  
Author(s):  
Yang Wang ◽  
Bo Liu ◽  
Xue Wang ◽  
Wei Zhao ◽  
Dongtao Liu ◽  
...  
Keyword(s):  
Ring Opening ◽  
Click Reaction ◽  
Star Polymers ◽  
Catalyst System ◽  
Ring Opening Polymerization

Building of various functional and topological microstructured PCLs via the immortal catalyst system of MgnBu2/ROH and click reaction.

scholarly journals Development of Four Unit Processes for Biobased PLA Manufacturing

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Chae Hwan Hong ◽  
Si Hwan Kim ◽  
Ji-Yeon Seo ◽  
Do Suck Han
Keyword(s):  
Lactic Acid ◽  
Ring Opening ◽  
Lactic Acid Production ◽  
Scale Up ◽  
Catalyst System ◽  
Ring Opening Polymerization ◽  
Acid Fermentation ◽  
Manufacturing Method ◽  
Renewable Biomass ◽  
Microbial Productivity

Polylactide (PLA), which is one of the most important biocompatible polyesters that are derived from annually renewable biomass such as corn and sugar beets, has attracted much attention for automotive parts application. The manufacturing method of PLA is the ring-opening polymerization of the dimeric cyclic ester of lactic acid, lactide. For the stereocomplex PLA, we developed the four unit processes, fermentation, separation, lactide conversion, and polymerization. Fermentation of sugars to D-lactic acid is little studied, and its microbial productivity is not well known. Therefore, we investigated D-lactic acid fermentation with a view to obtaining the strains capable of producing D-lactic acid, and we got a maximum lactic acid production 60 g/L. Lactide is prepared by a two-step process: first, the lactic acid is converted into oligo(lactic acid) by a polycondensation reaction; second, the oligo(lactic acid) is thermally depolymerized to form the cyclic lactide via an unzipping mechanism. Through catalyst screening test for polycondensation and depolymerization reactions, we got a new method which shortens the whole reaction time 50% the level of the conventional method. Poly(L-lactide) was obtained from the ring-opening polymerization of L-lactide. We investigated various catalysts and polymerization conditions. Finally, we got the best catalyst system and the scale-up technology.

TiCp2Cl-Catalyzed Living Radical and Ring Opening Polymerizations Initiated from Epoxides and Aldehydes in the Synthesis of Linear, Graft and Branched Polymers

2004 ◽  
Vol 856 ◽  
Author(s):  
Alexandru D. Asandei ◽  
Isaac W. Moran ◽  
Gobinda Saha ◽  
Yanhui Chen
Keyword(s):  
Electron Transfer ◽  
Ring Opening ◽  
Glycidyl Methacrylate ◽  
Ring Opening Polymerization ◽  
Branched Polymers ◽  
Single Electron Transfer ◽  
Radical Ring ◽  
Polymer Architectures ◽  
Complex Polymer

ABSTRACTTi(III)Cp2Cl-catalyzed radical ring opening (RRO) of epoxides or single electron transfer (SET) reduction of aldehydes generates Ti alkoxides and carbon centered radicals which add to styrene, initiating a radical polymerization. This polymerization is mediate in a living fashion by the reversible termination of growing chains with the TiCp2Cl metalloradical. In addition, polymers or monomers containing pendant epoxide groups (glycidyl methacrylate) can be used as substrates for radical grafting or branching reactions by self condensing vinyl polymerization. In addition, Ti alkoxides generated in situ by both epoxide RRO and aldehyde SET initiate the living ring opening polymerization of ε-caprolactone. Thus, new initiators and catalysts are introduced for the synthesis of complex polymer architectures.

scholarly journals Synthesis of polybenzoxazine/clay nanocomposites by in situ thermal ring-opening polymerization using intercalated monomer

2011 ◽  
Vol 49 (19) ◽  
pp. 4213-4220 ◽  
Author(s):  
Kubra Dogan Demir ◽  
Mehmet Atilla Tasdelen ◽  
Tamer Uyar ◽  
Asei William Kawaguchi ◽  
Atsushi Sudo ◽  
...  
Keyword(s):  
Ring Opening ◽  
Ring Opening Polymerization ◽  
Clay Nanocomposites

Lipase Catalyzed HEMA Initiated Ring-Opening Polymerization: In Situ Formation of Mixed Polyester Methacrylates by Transesterification

2008 ◽  
Vol 9 (2) ◽  
pp. 704-710 ◽  
Author(s):  
Mohamad Takwa ◽  
Yan Xiao ◽  
Neil Simpson ◽  
Eva Malmström ◽  
Karl Hult ◽  
...  
Keyword(s):  
Ring Opening ◽  
Ring Opening Polymerization ◽  
In Situ Formation

Biometal Derivatives as Catalysts for the Ring-Opening Polymerization of Trimethylene Carbonate. Optimization of the Ca(II) Salen Catalyst System

2006 ◽  
Vol 39 (13) ◽  
pp. 4374-4379 ◽  
Author(s):  
Donald J. Darensbourg ◽  
Wonsook Choi ◽  
Poulomi Ganguly ◽  
Casseday P. Richers
Keyword(s):  
Ring Opening ◽  
Catalyst System ◽  
Ring Opening Polymerization ◽  
Trimethylene Carbonate

Construction of polyphosphoesters with the main chain of rigid backbones and stereostructures via organocatalyzed ring-opening polymerization

2020 ◽  
Vol 11 (20) ◽  
pp. 3475-3480
Author(s):  
Yu-Jia Zheng ◽  
Guan-Wen Yang ◽  
Bo Li ◽  
Guang-Peng Wu
Keyword(s):  
Ring Opening ◽  
Main Chain ◽  
Catalyst System ◽  
Ring Opening Polymerization ◽  
System P ◽  
Organic Catalyst

A highly stereoregular polyphosphoester with a rigid cyclohexylene structure in the main chain was constructed via ring-opening polymerization (ROP) in the presence of an organic catalyst system.

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