Investigation of the Mechanism of Cationic Polymerization of ∊-Caprolactone

Ludvig, E. B.; Belen'kaya, B.G.

doi:10.1080/00222337408066400

Cited by 20 publications

(8 citation statements)

References 3 publications

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“…P n values were close to the [monomer] 0 /[catalyst] 0 ratio, indicating controlled/living polymerization. 70 The semilog kinetic plots were concave up, and this phenomenon (observed also by others, years later) was attributed to the particular feature of CROP of heterocyclic monomers: when a monomer is more basic than the corresponding polymer units, then the relative concentration of active species increases with conversion.…”

Section: Factors Influencing Crop Polymerizability According To Ace A...mentioning

confidence: 61%

“…Polymerization of PL and CL initiated with carbenium ions and proceeding by ACE was studied, starting in 1960, by two groups of Russian authors: Rosenberg et al 69 and Ludvig et al 70 The first cited group used a trimethyl oxonium cation with a SbCl 6 − counterion. Kinetic studies in CH 2 Cl 2 solvent and in bulk CL revealed slow termination with the rate constants ratio, k p /k t , equal to 750 at 25 °C.…”

Section: Factors Influencing Crop Polymerizability According To Ace A...mentioning

confidence: 99%

“…Ludvig) published a series of papers on the kinetics of cationic polymerization of PL and CL. 70 Polymerization was initiated/catalyzed with the reaction product of the acylium cation with diethyl ether (CH 3 C + (O)SbCl 6 − + (C 2 H 5 ) 2 O). The expected, simple acylium adduct was not formed.…”

Section: Factors Influencing Crop Polymerizability According To Ace A...mentioning

confidence: 99%

“…discussion of Ludvig's papers in the previous section). 50,70 In several following papers on the synthesis of cyclic esters, with various catalytic systems, these requirements were repeated when it was stated that polymerization proceeds according to the AMM.…”

Section: Amm Polymerization Of Cyclic Esters Initiated With Protic Co...mentioning

confidence: 99%

“…Another group of Russian polymer chemists (Laboratory of E.B. Ludvig) published a series of papers on the kinetics of cationic polymerization of PL and CL . Polymerization was initiated/catalyzed with the reaction product of the acylium cation with diethyl ether (CH 3 C + (O)SbCl 6 – + (C 2 H 5 ) 2 O).…”

Section: Crop Of Cyclic Esters According To the Ace Mechanismmentioning

confidence: 99%

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Activated Monomer Mechanism (AMM) in Cationic Ring-Opening Polymerization. The Origin of the AMM and Further Development in Polymerization of Cyclic Esters

Penczek

Pretula

2021

ACS Macro Lett.

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The origin of the activated monomer mechanism (AMM) in cationic ring-opening polymerization (CROP) is described first. Then, conditions leading to the active chain end (ACE) mechanism and AMM are compared, as well as methods allowing to distinguish between these two mechanisms. These methods are based on the “ion trapping” of the active ionic species using highly basic phosphines or by comparing ACE and AMM kinetics of polymerization. The major factors deciding on the actual mechanism include: basicity of the monomers, ring strain, and the presence of the protic additives in the reaction system. These factors are tabulated for major cyclic ethers and cyclic esters. The historically evolved subsequent steps of AMM in the polymerization of cyclic esters are described: from the first experiments with trialkyloxonium salts, precursors of protonic acids, and added alcohols, via HCl as catalyst, and then CF3S(O)2OH (polymerizing lactides) to the most popular derivatives of phosphoric acid, like diphenyl phosphate. Conditions allowing to synthesize poly(ε-caprolactone) (PCL), according to AMM-CROP, with molar mass up to 105 g·mol–1, are described as well as methods to polymerize CL with a protic initiator and acidic catalyst in one molecule. Then various methods enhancing the activity of the polymerizing systems are compared, based predominantly on hydrogen bonding, either to the polymer active end group (usually the hydroxyl group) or to the acid anion. Finally, kinetic equations for ACE and AMM are compared, and it is shown that the majority of the AMM-CROP systems, mostly studied for CL and lactides, proceed as living/controlled polymerizations. Since polymer end groups are hydroxyl groups, then, as it was shown in several papers, any initiator with one or many hydroxyl groups provides macromolecules with the corresponding architecture. The papers on synthetic methods are not discussed in detail.

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Section: Factors Influencing Crop Polymerizability According To Ace A...mentioning

confidence: 61%

Section: Factors Influencing Crop Polymerizability According To Ace A...mentioning

confidence: 99%

Section: Factors Influencing Crop Polymerizability According To Ace A...mentioning

confidence: 99%

Section: Amm Polymerization Of Cyclic Esters Initiated With Protic Co...mentioning

confidence: 99%

Section: Crop Of Cyclic Esters According To the Ace Mechanismmentioning

confidence: 99%

See 3 more Smart Citations

Activated Monomer Mechanism (AMM) in Cationic Ring-Opening Polymerization. The Origin of the AMM and Further Development in Polymerization of Cyclic Esters

Penczek

Pretula

2021

ACS Macro Lett.

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Telechelic Polymers

Yaǧcı

Nuyken

Graubner

2004

Encyclopedia of Polymer Science and Technology

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In this article common synthetic routes toward telechelics, which are polymers with well‐defined functional end groups, are described. Telechelic polymers are available via radical, cationic, and anionic polymerization including reversible addition–fragmentation chain transfer polymerization, atom transfer radical polymerization, and nitroxide mediated polymerization. Furthermore, metathesis has become a valuable tool for the preparation of telechelics. Last but not least selected examples are presented in which step‐growth polymerization has been successfully applied for the synthesis of such well‐defined macromolecules. In specific cases chain scission can also be a useful route.

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Polylactones, 2 Copolymerization of glycolide with β‐propiolactone, γ‐butyrolactone or δ‐valerolactone

1985

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Numerous copolymerizations of glycolide with P-propiolactone, y -butyrolactone or 6-valerolactone were conducted either in bulk or in nitrobenzene solution at temperatures in the range of 20 to 150 "C. Three classes of catalysts were used, namely acidic catalysts initiating cationic polymerizations, complexing catalysts initiating insertion mechanisms, and anionic catalysts. The molar composition of the copolyesters was determined from 'H NMR spectra and the sequence distribution of the comonomers from 13C NMR spectra. No reasonable copolymerization of glycolide and P-propiolactone was obtained at 20 "C in nitrobenzene, whereas all catalysts yielded copolyesters at 100 "C. In the case of glycolide/y -butyrolactone only bulk copolymerizations at 60 "C with acidic initiators were successful. Under other conditions only homopolymerization of glycolide was observed. Copolymerizations of glycolide and y-valerolactone were performed in bulk and in nitrobenzene with both acidic and complexing initiators, whereas anionic initiators only caused homopolymerization of glycolide. Acidic initiators favored the incorporation of 6valerolactone, whereas the complexing initiators favored the incorporation of glycolide. The crystallinity of the glycolide/&valerolactone copolymers was characterized by means of differential scanning calorimetry, and a good agreement with the expectations from both molar composition and sequence distribution was found.

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Investigation of the Mechanism of Cationic Polymerization of ∊-Caprolactone

Cited by 20 publications

References 3 publications

Activated Monomer Mechanism (AMM) in Cationic Ring-Opening Polymerization. The Origin of the AMM and Further Development in Polymerization of Cyclic Esters

Activated Monomer Mechanism (AMM) in Cationic Ring-Opening Polymerization. The Origin of the AMM and Further Development in Polymerization of Cyclic Esters

Telechelic Polymers

Polylactones, 2 Copolymerization of glycolide with β‐propiolactone, γ‐butyrolactone or δ‐valerolactone

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