Carbon dioxide-based copolymers with various architectures

Yang, Li; Zhang, Yingying; Hu, Lan‐Fang; Zhang, Xinghong; Du, Binyang; Xu, Jun‐Ting

doi:10.1016/j.progpolymsci.2018.02.001

Cited by 127 publications

(66 citation statements)

References 304 publications

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“…[11] In order to expand the application scopes of biodegradable polymers resulted from ROCOP,i ntensive research efforts have been directed to the rational design and synthesis of block copolymers by combining ROCOP and other living/ controlled polymerization techniques. [12] We have reported the one-step synthesis of well-defined CO 2 -based block copolymers via concurrent ROCOP and RAFT polymerization using ab ifunctional chain transfer agent in 2018, however, only conjugated monomers such as methyl methacrylate (MMA) and styrene (St) were involved. [12b] In ar ecent contribution, we have illustrated am echanistic switch involving ROCOP and OMRP with a( Salen)Co system as catalyst/mediator for both mechanisms.T he switch operated in the OMRP-to-ROCOP direction via aO 2 -trig-gered modification of the polymer chain end from CoÀRt o CoÀOR and was implemented for the development of diblock copolymers with ap oly(vinyl acetate) block and ap olycarbonate block (by ROCOP of CO 2 /epoxides).…”

Section: Introductionmentioning

confidence: 99%

Switchable Polymerization Triggered by Fast and Quantitative Insertion of Carbon Monoxide into Cobalt–Oxygen Bonds

et al. 2020

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A strategy that uses carbon monoxide (CO) as a molecular trigger to switch the polymerization mechanism of a cobalt Salen complex [salen=(R,R)‐N,N′‐bis(3,5‐di‐tert‐butylsalicylidene)‐1,2‐cyclohexanediamine] from ring‐opening copolymerization (ROCOP) of epoxides/anhydrides to organometallic mediated controlled radical polymerization (OMRP) of acrylates is described. The key phenomenon is a rapid and quantitative insertion of CO into the Co−O bond, allowing for in situ transformation of the ROCOP active species (Salen)CoIII‐OR into the OMRP photoinitiator (Salen)CoIII‐CO2R. The proposed mechanism, which involves CO coordination to (Salen)CoIII‐OR and subsequent intramolecular rearrangement via migratory insertion has been rationalized by DFT calculations. Regulated by both CO and visible light, on‐demand sequence control can be achieved for the one‐pot synthesis of polyester‐b‐polyacrylate diblock copolymers (Đ<1.15).

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Section: Introductionmentioning

confidence: 99%

Switchable Polymerization Triggered by Fast and Quantitative Insertion of Carbon Monoxide into Cobalt–Oxygen Bonds

et al. 2020

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“…One common strategy for tuning the polymer properties such as glass transition temperature ( T g ) is to incorporate additional monomers to form block or random copolymers [ 51 , 52 , 53 , 54 ]. Given the versatility of the current zinc catalysts for various epoxides and anhydrides, we were interested to see if terpolymerization could be achieved and how it could affect the properties of the resulting terpolymers.…”

Section: Resultsmentioning

confidence: 99%

Zinc Amido-Oxazolinate Catalyzed Ring Opening Copolymerization and Terpolymerization of Maleic Anhydride and Epoxides

et al. 2020

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Ring opening copolymerization (ROCOP) of epoxides and cyclic anhydrides has become an attractive approach for the synthesis of biodegradable polyesters with various compositions. Encouraged by the efficiency and versatility of a series of amido-oxazolinate zinc complexes, in this study they were shown to be active catalysts for the synthesis of unsaturated polyesters via ROCOP of maleic anhydride and various epoxides. The relative activity of epoxides in these reactions was observed to be styrene oxide > cyclohexene oxide > phenyl glycidyl ether, which could be correlated with the electronic and steric features of the substrate. To provide more structural possibilities for the polyesters, the difference in epoxide reactivity was exploited in an attempt to prepare block terpolymers from one anhydride and two epoxides. Terpolymerization was carried out in one or two steps in a single pot. The thermal characterization by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) techniques suggested that the resulting materials were mostly random terpolymers.

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“…The total number of chains in such a regime will favorably exceed the number of active catalyst sites. In addition, blockcopolycarbonates can be obtained by the strategy as was recently summarized in an extensive review, comprising many mechanistic considerations [57].…”

Section: Introductionmentioning

confidence: 99%

DMC-Mediated Copolymerization of CO2 and PO—Mechanistic Aspects Derived from Feed and Polymer Composition

Stahl

Luinstra

2020

Catalysts

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The influence of composition of liquid phase on composition of poly(propylene ether carbonates) in the copolymerization of CO2 with propylene oxide (PO), mediated by a zinc chloride cobalt double metal cyanide, was monitored by FT-IR/CO2 uptake/size exclusion chromatography in batch and semi-batch mode. The ratio of mol fractions of carbonate to ether linkages F (~0.15) was found virtually independent on the feed between 60 and 120 °C. The presence of CO2 lowers the catalytic activity but yields more narrowly distributed poly(propylene ether carbonates). Hints on diffusion and chemistry-related restrictions were found underlying, broadening the distribution. The incorporation of CO2 seems to proceed in a metal-based insertion chain process, ether linkages are generated stepwise after external nucleophilic attack. The presence of amines resulted in lower activities and no change in F. An exchange of chloride for nitrate in the catalyst led to a higher F of max. 0.45. The observations are interpreted in a mechanistic scheme, comprising surface-base-assisted nucleophilic attack of external weak nucleophiles and of mobile surface-bound carboxylato entities on activated PO in competition to protonation of surface-bound alkoxide intermediates by poly(propylene ether carbonate) glycols or by surface-bound protons. Basic entities on the catalyst may promote CO2 incorporation.

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Carbon dioxide-based copolymers with various architectures

Cited by 127 publications

References 304 publications

Switchable Polymerization Triggered by Fast and Quantitative Insertion of Carbon Monoxide into Cobalt–Oxygen Bonds

Switchable Polymerization Triggered by Fast and Quantitative Insertion of Carbon Monoxide into Cobalt–Oxygen Bonds

Zinc Amido-Oxazolinate Catalyzed Ring Opening Copolymerization and Terpolymerization of Maleic Anhydride and Epoxides

DMC-Mediated Copolymerization of CO2 and PO—Mechanistic Aspects Derived from Feed and Polymer Composition

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