scholarly journals Bimetallic Chromium Catalysts with Chain Transfer Agents: A Route to Isotactic Poly(propylene oxide)s with Narrow Dispersities

2018 ◽  
Vol 57 (20) ◽  
pp. 5731-5734 ◽  
Author(s):  
Lilliana S. Morris ◽  
M. Ian Childers ◽  
Geoffrey W. Coates
2021 ◽  
Vol 12 (9) ◽  
pp. 1260-1272
Author(s):  
Daniel Grunenberg ◽  
Katharina Ehrmann ◽  
Christian Gorsche ◽  
Bernhard Steyrer ◽  
Thomas Koch ◽  
...  

Linking an addition–fragmentation-chain-transfer (AFCT) functionality and methacrylate moiety via poly(propylene oxide)-oligomer within one molecule creates a non-migrating AFCT-reagent aiding network-homogeneity.


Catalysts ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 632
Author(s):  
Kirill Alferov ◽  
Shuanjin Wang ◽  
Tianhao Li ◽  
Min Xiao ◽  
Shanyue Guan ◽  
...  

Synthesis of copolymers from carbon dioxide (CO2) and epoxides is an important research direction as such processes utilize the abundant greenhouse gas and deliver useful products. Specifically, cooligomers of CO2 and propylene oxide (PO) with a non-alternating structure can be used for polyurethane preparation. They are synthesized by employing Zn-Co cyanide catalysts. The application of alternative metal cyanide complexes is interesting from scientific and practical points of view. The purpose of this work was to study the copolymerization of CO2 and PO in the presence of Co-Ni cyanide catalysts and chain transfer agents (CTAs) in order to obtain low molecular weight products. Three Co-Ni catalysts with different contents of complexing agents were synthesized, characterized by several analytical methods and applied for this reaction. The complex without complexing agents was chosen for detailed investigation. 1,6-Hexanediol proved to be a more preferred CTA than poly(propylene glycol) and adipic acid. An oligo(ethercarbonate) (Mn = 2560, PDI = 2.5, CO2 = 20 mol.%) capped with OH groups was synthesized with relatively high productivity (1320 gPO+CO2/gcat in 24 h) and characterized by matrix-assisted laser desorption/ionization (MALDI) MS and NMR methods. The main chain transfer routes during the cooligomerization were suggested on the basis of the research results.


2016 ◽  
Vol 2016 ◽  
pp. 1-6 ◽  
Author(s):  
Zbigniew Grobelny ◽  
Andrzej Swinarew ◽  
Justyna Jurek-Suliga ◽  
Kinga Skrzeczyna ◽  
Jadwiga Gabor ◽  
...  

Potassiumt-butoxide dissolved in tetrahydrofuran effectively initiates homogeneous polymerization of propylene oxide at room temperature. Unsaturation and molar mass (Mn) of the polymers prepared depend on the presence of additives, such as macrocyclic ligand 18-crown-6 (L) andt-butanol. Application of the ligand alone results in distinct increase of unsaturation and decrease ofMn, whereas use oft-BuOH leads to simultaneous decrease of unsaturation andMn. Activation oft-BuOK/t-BuOH system with the ligand causes further decrease of unsaturation, that is, from 12.0 to 3.5 mol % for OK/OH (1/3) and OK/OH/L (1/3/2) systems, respectively. Unexpectedly,Mnof the polymers obtained does not practically change (~4800). This result differs from that reported earlier for neat PO polymerization initiated potassium 1-methoxy-2-propoxide/1-methoxy-2-propanol, in which in the presence of the same ligandMnincreases to ~12 400 for the same ratio of reagents. The mechanism of studied processes was discussed.


2021 ◽  
Vol 12 (12) ◽  
pp. 1776-1786
Author(s):  
Zhou Wang ◽  
Ying Mu

Stereoregular poly(propylene carbonate)s and poly(propylene succinate-block-carbonate)s were synthesized with new chiral salenCo(iii) catalysts carrying bulky substituents.


RSC Advances ◽  
2021 ◽  
Vol 11 (15) ◽  
pp. 8782-8792
Author(s):  
Ningzhang Liu ◽  
Chuanhai Gu ◽  
Qinghe Wang ◽  
Linhua Zhu ◽  
Huiqiong Yan ◽  
...  

For poly(propylene carbonate trimellitic anhydride) with good yield, thermal stability and high molecular weight, a catalyst of zinc glutarate/rare earth ternary complex/double metal cyanide was used for terpolymerization of CO2, propylene oxide and trimellitic anhydride.


1986 ◽  
Vol 19 (5) ◽  
pp. 1337-1343 ◽  
Author(s):  
Frederic C. Schilling ◽  
Alan E. Tonelli

2011 ◽  
Vol 53 (7-8) ◽  
pp. 437-447 ◽  
Author(s):  
E. V. Chernikova ◽  
V. V. Yulusov ◽  
K. O. Mineeva ◽  
V. B. Golubev ◽  
E. S. Garina

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