Activated monomer cationic polymerization of 1,3-dioxepan-2-one initiated by water-hydrogen chloride

Shibasaki, Yuji; Sanda, Fumio; Endō, Takeshi

doi:10.1002/(sici)1521-3927(19991001)20:10<532::aid-marc532>3.0.co;2-e

Cited by 35 publications

(29 citation statements)

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“…These characteristic features of cationic ring‐opening polymerization proceeding by the AM mechanism have stimulated interest in expanding the scope of its application to other classes of monomers. Thus, the cationic AM mechanism has been applied to the homopolymerization and copolymerization of epoxides,7–12 oxetanes,13 and cyclic acetals,14, 15 as well as polymerizations of cyclic esters (lactones), including cyclic carbonates 16–22. Recently, the cationic homopolymerization of lactide proceeding by the AM mechanism has also been described 23…”

Section: Introductionmentioning

confidence: 99%

“…Thus, the cationic AM mechanism has been applied to the homopolymerization and copolymerization of epoxides, 7-12 oxetanes, 13 and cyclic acetals, 14,15 as well as polymerizations of cyclic esters (lactones), including cyclic carbonates. [16][17][18][19][20][21][22] Recently, the cationic homopolymerization of lactide proceeding by the AM mechanism has also been described. 23 In this article, we report the cationic copolymerization of e-caprolactone (CL) with L,L-lactide (LA) under conditions of AM polymerization.…”

Section: Introductionmentioning

confidence: 99%

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Cationic copolymerization of ε‐caprolactone and L,L‐lactide by an activated monomer mechanism

Baśko

Kubisa

2006

J. Polym. Sci. A Polym. Chem.

110

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The cationic homopolymerization and copolymerization of L,L‐lactide and ε‐caprolactone in the presence of alcohol have been studied. The rate of homopolymerization of ε‐caprolactone is slightly higher than that of L,L‐lactide. In the copolymerization, the reverse order of reactivities has been observed, and L,L‐lactide is preferentially incorporated into the copolymer. Both the homopolymerization and copolymerization proceed by an activated monomer mechanism, and the molecular weights and dispersities are controlled {number‐average degree of polymerization = ([M]0 − [M]t)/[I]0, where [M]0 is the initial monomer concentration, [M]t is the monomer concentration at time t, and [I]0 is the initial initiator concentration; weight‐average molecular weight/number‐average molecular weight ∼1.1–1.3}. An analysis of 13C NMR spectra of the copolymers indicates that transesterification is slow in comparison with propagation, and the microstructure of the copolymers is governed by the relative reactivity of the comonomers. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 7071–7081, 2006

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Cationic copolymerization of ε‐caprolactone and L,L‐lactide by an activated monomer mechanism

Baśko

Kubisa

2006

J. Polym. Sci. A Polym. Chem.

110

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“…The strong Brønsted acids are only effective ROP catalysts for specific substrates, such as 1,3-dioxepan-2-one [147], and only several types of Brønsted and Lewis acids demonstrated the high efficiency in ROP of common cyclic esters, such as δVL, εCL, TMC, or LA. The ability of sulfonic acids [148][149][150][151][152][153][154][155][156][157][158][159], carboxylic acids [160][161][162][163], acidic phosphates [164][165][166][167], ROH/HCl/ether [168][169][170], and Tf 2 NH [171] to catalyze polymerization of the common lactones, cyclic carbonates, and lactides has been established, the mechanisms of the reactions were proposed but not explored in detail. In [150], the thermochemistry of cationic ring-opening of TMC and 5-methylene-1,3-dioxan-2-one was estimated by quantum-chemical modeling at the HF/3-21G** level of theory, but the results of such modeling do not correspond to the subject of our review.…”

Section: Acid-catalyzed Ropmentioning

confidence: 99%

DFT Modeling of Organocatalytic Ring-Opening Polymerization of Cyclic Esters: A Crucial Role of Proton Exchange and Hydrogen Bonding

Nifant’ev

Ivchenko

2019

Polymers

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Organocatalysis is highly efficient in the ring-opening polymerization (ROP) of cyclic esters. A variety of initiators broaden the areas of organocatalysis in polymerization of different monomers, such as lactones, cyclic carbonates, lactides or gycolides, ethylene phosphates and phosphonates, and others. The mechanisms of organocatalytic ROP are at least as diverse as the mechanisms of coordination ROP; the study of these mechanisms is critical in ensuring the polymer compositions and architectures. The use of density functional theory (DFT) methods for comparative modeling and visualization of organocatalytic ROP pathways, in line with experimental proof of the structures of the reaction intermediates, make it possible to establish these mechanisms. In the present review, which continues and complements our recent manuscript that focused on DFT modeling of coordination ROP, we summarized the results of DFT modeling of organocatalytic ROP of cyclic esters and some related organocatalytic processes, such as polyester transesterification. 4 of 49 were found to be polymerizable due to strain in the ester group. In addition, the predominance of high-energy coiled conformations in linear homopolymers the formed from PDO, εCL and GL was proportionately less than extended conformations, in comparison to the inactive monomer γBL. However, while the prevalence of coiled conformations over extended conformations was expected for poly(LA), this factor does not affected the reactivity of lactides. Very good agreement between the experimental and calculated data for ROP of GL, l-LA and (R,S)-lactide [47] should be separately noted. 4-(Dimethylamino)pyridine (DMAP) and Related CompoundsDMAP was the first employed organocatalyst in polymer synthesis. In 2001, Nederberg et al. [48] reported the "first organocatalytic living polymerization" (Ð M < 1.2) of L-lactide (l-LA) mediated by DMAP or 4-pyrrolidinopyridine in the presence of ROH initiators. Four years later [49], Feng and Dong reported polymerization of ε-caprolactone (εCL) catalyzed by DMAP in the presence of chitozane as an initiator. Bourissou et al. studied the mechanism of DMAP-catalyzed ROP of l-LA and five-membered lactic O-carboxylic anhydride (lacOCA) [50]. Two possible reaction pathways were analyzed at the B3LYP/6-31G(d) level of theory [39,40,51]; the solvent effect of dichloromethane was taken into account through the PCM/SCRF model [52]. The modeled reaction was the methanolysis of l-LA or lacOCA; alternative nucleophilic/monomer (Scheme 1a) and basic/alcohol (Scheme 1b) activation mechanisms were proposed for these reactions, and then analyzed by DFT optimization of the key reaction intermediates and transition states, if necessary. Scheme 1. Schematic representation of the nucleophilic/monomer (a) and basic/alcohol (b) mechanisms for (Dimethylamino)pyridine (DMAP)-catalyzed methanolysis of l-LA. Author Contributions: Conceptualization, P.I.; Methodology, I.N. and P.I.; Writing-Original draft preparation, P.I.; Writing-Review and editing, I.N. and P.I.; V...

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“…A drawback of this polymerization method is the need of high purity monomers, especially when larger amounts are used, thereby limiting the polymer production on multigram scale. However, in the last years various monomers with different functionalities have been developed synthetically which allow larger scale production, even if several purification steps are required before use …”

Section: Introductionmentioning

confidence: 99%

“…However, in the last years various monomers with different functionalities have been developed synthetically which allow larger scale production, even if several purification steps are required before use. 3,19,20 It is well known that in CROP two polymerization mechanisms can coexist: the activated chain end (ACE) and activated monomer (AM) mechanisms. 17 Furthermore, other side reactions such as intramolecular transesterification or backbiting producing cyclic species, or decarboxylation producing ether linkages, can also occur.…”

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confidence: 99%

Effect of a Set of Acids and Polymerization Conditions on the Architecture of Polycarbonates Obtained via Ring Opening Polymerization

Jiménez-Pardo

Ven

Benthem

et al. 2017

J. Polym. Sci. Part A: Polym. Chem.

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Polycarbonate‐based polymers with a well‐defined architecture have become interesting materials due to their large range of applications. Ring opening polymerization (ROP) has been largely applied to make branched polycarbonates. The polymer architectures obtained via this method are strictly related with the polymerization mechanisms involved which depend on the polymerization conditions chosen. Hereby, we evaluate the catalytic activity of three acids, fumaric, trifluoroacetic, and methanesulfonic on the Cationic ROP of trimethylene carbonate (TMC) over a trifunctional initiator, trimethylol propane (TMP), under different reaction conditions. In‐detail characterization of the polymers showed the co‐existence of two polymerization mechanisms: the activated monomer (AM), which produces a tri‐armed branched polycarbonate with inclusion of the TMP initiator (TMP‐PTMC), and a combined AM/Activated Chain End (ACE) mechanism, which produces a linear polycarbonate (L‐PTMC). Such mixtures were identified for nearly all the reaction variables investigated, together with other side reactions. Upon optimization of the synthesis, the polymerizations in toluene with TFA at 35 °C and equimolar acid/initiator ratio were optimal, avoiding side reactions, but still resulting in a polymer mixture composed of ∼69% TMP‐PTMC and 31% of a polycarbonate linear polymer. The occurrence of such mixed polymer architectures is commonly overlooked in literature regarding CROP of branched polycarbonates. We demonstrate the importance of performing a full characterization for a successful detection of polymer mixtures having different (number of) end‐functionalities, which are critical for further use in advanced applications, such as in the biomedical or pharmaceutical filed. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017, 55, 1502–1511

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Activated monomer cationic polymerization of 1,3-dioxepan-2-one initiated by water-hydrogen chloride

Cited by 35 publications

References 1 publication

Cationic copolymerization of ε‐caprolactone and L,L‐lactide by an activated monomer mechanism

Cationic copolymerization of ε‐caprolactone and L,L‐lactide by an activated monomer mechanism

DFT Modeling of Organocatalytic Ring-Opening Polymerization of Cyclic Esters: A Crucial Role of Proton Exchange and Hydrogen Bonding

Effect of a Set of Acids and Polymerization Conditions on the Architecture of Polycarbonates Obtained via Ring Opening Polymerization

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