Cyclodextrins in polymer synthesis: Steric retardation of the free-radical polymerization in aqueous medium of 4-vinylbenzaldehyde/methylated -cyclodextrin complex

Heinenberg, Michael; Ritter, Helmut

doi:10.1002/1521-3935(200208)203:12<1804::aid-macp1804>3.0.co;2-3

Cited by 8 publications

(8 citation statements)

References 15 publications

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“…Among these polymers, polymers bearing aldehyde functionalities are attractive because aldehydes are among the most reactive substrates for FGT under mild reaction conditions however, the resulting polymers lacked well-defined structures due to the nonliving nature of the polymerization technique. − Anionic polymerization provided an alternative synthetic pathway for the preparation of aldehyde-functionalized polymers, − but the stringent polymerization conditions and tedious preparation procedures (protection of monomer, polymerization, and deprotection of the resulting polymers were required) significantly restrict the applicability of this synthetic route.…”

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confidence: 99%

Reversible Addition Fragmentation Chain Transfer Polymerization of 4-Vinylbenzaldehyde

Sun¹,

Cheng²,

Wooley³

2007

Macromolecules

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The direct reversible addition fragmentation chain transfer (RAFT) polymerization of 4-vinylbenzaldehyde (VBA) was established as a new synthetic method for the preparation of welldefined poly(vinylbenzaldehyde) (PVBA), a polymer having reactive aldehyde side chain substiuents. RAFT polymerization of VBA was investigated using S-1-dodecyl-S'-(α,α'-dimethyl-α"-acetic acid)trithiocarbonate (DDMAT) as chain transfer agent (CTA) and 2,2′-azobis (isobutyronitrile) (AIBN) as initiator in 1,4-dioxane or 2-butanone at 70-75 °C for 7.5-22.5 h. With 45-76% of monomer conversion, the resulting PVBA had well controlled number-average molecular weight (M n ) and low polydispersity (PDI < 1.17). The living characteristic of the RAFT polymerization process was confirmed by the linearity between the M n values of PVBA and monomer conversions. Well-defined PVBA was further used as a macromolecular chain transfer agent (macro-CTA) in RAFT polymerization of styrene (St), and a block copolymer PVBA-b-PSt with relatively low polydispersity (PDI = 1.20) was successfully synthesized.Construction of polymers with highly reactive functionalities that allow for further diverse functional group transformation (FGT) is an emerging research area in modern polymer chemistry. 1 Among these polymers, polymers bearing aldehyde functionalities are attractive because aldehydes are among the most reactive substrates for FGT under mild reaction conditions. 2 Conventional radical polymerization of aldehyde-functionalized monomers has been studied since 1950s, 3 however, the resulting polymers lacked well-defined structures, due to the non-living nature of the polymerization technique. 4-7 Anionic polymerization provided an alternative synthetic pathway for the preparation of aldehyde-functionalized polymers, 8-13 but the stringent polymerization conditions and tedious preparation procedures (protection of monomer, polymerization, and deprotection of the resulting polymers were required) significantly restrict the applicability of this synthetic route.To efficiently prepare well-defined aldehyde-functionalized polymers, we investigated living radical polymerization of aldehyde-functionalized monomers. In the past decade, reversible addition fragmentation chain transfer (RAFT) polymerization has been developed and demonstrated as a powerful tool in living radical polymerization. 14,15 Relative to other living radical polymerization techniques, one important advantage of RAFT is that it provides facile and homogenous living polymerization systems applicable for a wide variety of monomers under relatively mild reaction conditions. In this communication, we report our recent work of RAFT polymerization of 4-vinylbenzaldahyde (VBA), as a new methodology for the construction of well-defined aldehyde-functionalized polymers (Scheme 1). Several synthetic pathways for the synthesis of VBA have been reported in the literature, including transition metal-catalyzed cross-coupling of 4-bromobenzaldehyde with ethylene or vinyl reagents, Grignard addition t...

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confidence: 99%

Reversible Addition Fragmentation Chain Transfer Polymerization of 4-Vinylbenzaldehyde

Sun¹,

Cheng²,

Wooley³

2007

Macromolecules

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“…The influence of CD on the kinetics and molecular weight is strongly dependent on the monomer. Accordingly, Me‐ β ‐CD‐complexed acrylates show different copolymerization parameters in comparison to the free monomers in organic solvents, which was explained by different complex stabilities 33,34…”

Section: Resultsmentioning

confidence: 99%

“…In order to obtain information about the mechanism, the kinetics of the polymerization of various monomers29,30 as well as the influence of chain‐transfer agents31,32 was investigated. In addition, examples whereby CDs hinder the polymerization are known 33. Furthermore, the influence of CD on the copolymerization parameters of hydrophobic monomers was examined 34,35.…”

Section: Introductionmentioning

confidence: 99%

Cyclodextrins in Polymer Synthesis: Free Radical Polymerization of β‐Cyclodextrin Complexes of Photosensitive Mesoionic 6‐Oxo‐1,6‐dihydropyrimidin‐3‐ium‐4‐olates in Aqueous Medium

Theis¹,

Ritter²

2003

Macro Chemistry & Physics

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Solid mesoionic 2‐[2‐(isopropenylcarbonyloxy)ethylthio]‐1‐methyl‐6‐oxo‐3‐phenyl‐5‐propyl‐1,6‐dihydropyrimidin‐3‐ium‐4‐olate was complexed in water using β‐cyclodextrin (β‐CD) and randomly methylated β‐CD, which resulted in polymerizable complexes with 2:1 stoichiometry. The β‐CD complex was characterized using 1H NMR, ROESY NMR and UV spectroscopy. Polymerization of the complex prepared from methylated β‐CD led to a photosensitive polymer, which precipitated during polymerization and was nearly free of CD. Polymerization was carried out with a water‐soluble redox initiator. In addition, a copolymer with methyl methacrylate was prepared from the complexes, which showed a different mass‐dependent distribution in the incorporation in comparison to a copolymer prepared without CD in organic solvents.magnified image

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“…The hydrophobic cavity of CDs binds suitable organics by hydrophobic interactions and/or H-bonds, while the hydrophilic outer shell provides the water solubility. Ritter et al successfully polymerized various hydrophobic monomers, such as styrene [33][34][35][36][37][38], (meth)acrylates [33,34,[39][40][41][42][43][44], phenol derivatives [45,46], fumarates [47,48], dienes [49,50], halo-olefins [51][52][53], and other non-commercial ones [54][55][56][57][58][59][60][61] in water, solubilized by CD, via free radical polymerization methods. During the polymerization, the CD, every time, slips off from the last monomeric unit of the polymer, and the product precipitates, resulting in a pure product, or simple purification.…”

Section: Introductionmentioning

confidence: 99%

New, Aqueous Radical (Co)Polymerization of Olefins at Low Temperature and Pressure

Hero

Kali

2020

Processes

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In this communication, we describe our preliminary results for the development of a new method of ethylene and propene (co)polymerization at low pressure at room temperature, using cyclodextrin-assisted aqueous radical polymerization for the first time. For polypropylene homopolymerization, the cyclodextrin was entirely removed, and the partially soluble polymer was characterized. The purification of polyethylene was not complete, since the threaded cyclodextrins remained on the polymer chain, enhancing its solubility and enable to analyze the sample. With this environmentally benign method, polyolefines could be produced, for the first time. The estimated yield was low, and therefore the conditions should be further tuned for industrial application. This straightforward approach could also be applied to synthesize poly(ethylene-co-vinyl acetate) copolymer with an ethylene content of 20 mol% and enhanced yield. Although the procedure in this stage of research has some limitations, the theory behind can later be applied to develop new, energy-efficient, and versatile industrial processes for olefin copolymerizations for a wide range of comonomers.

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Cyclodextrins in polymer synthesis: Steric retardation of the free-radical polymerization in aqueous medium of 4-vinylbenzaldehyde/methylated -cyclodextrin complex

Cited by 8 publications

References 15 publications

Reversible Addition Fragmentation Chain Transfer Polymerization of 4-Vinylbenzaldehyde

Reversible Addition Fragmentation Chain Transfer Polymerization of 4-Vinylbenzaldehyde

Cyclodextrins in Polymer Synthesis: Free Radical Polymerization of β‐Cyclodextrin Complexes of Photosensitive Mesoionic 6‐Oxo‐1,6‐dihydropyrimidin‐3‐ium‐4‐olates in Aqueous Medium

New, Aqueous Radical (Co)Polymerization of Olefins at Low Temperature and Pressure

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