Influence of structural parameters on the degradation of ultrahigh‐molecular‐weight vinyl‐type network‐polymer precursors during elution through size exclusion chromatography columns

Ikeda, Junichi; Oe, Hiroaki; Aota, Hiroyuki; Matsumoto, Akira

doi:10.1002/app.12778

Cited by 5 publications

(4 citation statements)

References 17 publications

(17 reference statements)

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“…The slopes of the correlation lines of M w versus elution volume shifted a bit upward with conversion but any specific correlation lines were not observed al all as opposed to the case of the cationic crosslinking ECH/BECHMA(80/20) copolymerization, especially at the conversion close to the gel point. Moreover, the M w value of the ECH/BECHMA(80/20)‐NPP obtained at 49.1%, very close to the gel‐point conversion of 49.6%, was estimated to be only 5.0 × 10 5 , although the exclusion limit of SEC was much higher at 2 × 10 7 ; this will be discussed later in connection with the degradation of ultrahigh‐molecular‐weight NPPs during elution through SEC columns 51, 52…”

Section: Resultsmentioning

confidence: 86%

“…That is, the molecular weights determined by SEC‐MALLS were compared with those by LS. Because M w (SEC‐MALLS)/ M w (LS) would be a measure of the degradation of the NPP during elution through the SEC columns, the most remarkable degradation was observed for the NPP with the most flexible backbone chains, typical exemplified by benzyl acrylate/1,6‐hexanediol diacrylate copolymerization 52. The results were correlated with the structural parameters of NPPs, including primary polymer chain length, branched structure, and multiple crosslink or network structure.…”

Section: Resultsmentioning

confidence: 94%

“…Our previous articles51, 52 dealt with the free‐radical crosslinking monovinyl/divinyl copolymerizations as an extension of our continuing studies concerned with the mechanistic discussion of the three‐dimensional network formation in crosslinking multivinyl polymerization 1. During the detailed pursuit of the variation in molecular weight distribution curves with conversion by SEC‐MALLS, we noticed by chance that the degradation of an ultrahigh‐molecular‐weight NPP obtained at a conversion close to the gel point occurred significantly during elusion through SEC columns.…”

Section: Resultsmentioning

confidence: 99%

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Mechanistic discussion of cationic crosslinking copolymerizations of 1,2‐epoxycyclohexane with diepoxide crosslinkers accompanied by intramolecular and intermolecular chain transfer reactions

Katahira¹,

Morishita²,

Ikeda

et al. 2010

J. Polym. Sci. A Polym. Chem.

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Our previous mechanistic discussion of the free‐radical crosslinking monoallyl/diallyl copolymerizations was extended to the cationic crosslinking monoepoxide/diepoxide copolymerizations, typically including 1,2‐epoxycyclohexane (ECH) as a monoepoxide and bis[3,4‐epoxycyclohexylmethyl] adipate (BECHMA) as a diepoxide crosslinker. In the cationic polymerization, oligomer is usually obtained because of the occurrence of characteristic chain‐forming reactions. Therefore, cationic crosslinking monoepoxide/diepoxide copolymerizations could be in the category of the network formation through free‐radical crosslinking monoallyl/diallyl copolymerizations. Thus, the gelation behavior was discussed by comparing the actual gel points with the theoretical ones; the greatly delayed gelation from theory was observed. Then, the resulting network polymer precursors (NPPs) were characterized by SEC‐MALLS‐viscometry to clarify the cationic crosslinking ECH/BECHMA copolymerization mechanism. Notably, the correlation lines of molecular weight versus elution volume were specific for the NPPs obtained at a high conversion close to the gel point as compared with those obtained by the free‐radical crosslinking monoallyl/diallyl copolymerization. This may be ascribed to the occurrence of intramolecular and intermolecular chain transfer reactions characteristic of cationic polymerization; the chain transfer reactions involve the intramolecular and intermolecular nucleophilic attack of ether oxygen or terminal hydroxyl oxygen in the NPPs to a terminal growing cation that leads to the formation of not only the loop‐ but also the crosslink‐structures containing NPPs, providing fragile ultrahigh‐molecular‐weight NPP in the SEC columns. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010

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Section: Resultsmentioning

confidence: 86%

Section: Resultsmentioning

confidence: 94%

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Mechanistic discussion of cationic crosslinking copolymerizations of 1,2‐epoxycyclohexane with diepoxide crosslinkers accompanied by intramolecular and intermolecular chain transfer reactions

Katahira¹,

Morishita²,

Ikeda

et al. 2010

J. Polym. Sci. A Polym. Chem.

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“…[17] During the progress of our investigation, we noticed by chance that the degradation of NPPs with ultrahigh molecular weight obtained at a conversion close to the gel point occurred significantly during elution through SEC columns. [18,19] That is, the molecular weights determined by both SEC-MALLS and light scattering (LS) measurements were compared in detail. Although both results were in a good agreement within experimental errors for NPPS of moderate molecular weight less than one million, the discrepancy between both measurements became greater with further increment of molecular weight, i.e., with the progress of polymerization.…”

Section: Pursuit Of Ideal Npp Formationmentioning

confidence: 99%

Construction of Crosslink‐System‐Materials Utilizing Designed Network‐Polymer‐Precursor Modules

Matsumoto

2011

Macromolecular Symposia

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Summary: For a long time, we have been concerned with the elucidation of network formation mechanism of free-radical crosslinking (co)polymerization of multivinyl monomers. We have pursued two extreme network structures formation such as ideal and nanogel-like NPP formation. During the course of these investigations, we recognized that a network polymer may be reconsidered as a crosslink-systemmaterial (CSM) or a giant system consisting of network polymer precursor (NPP) modules. The network polymer is not a giant molecule as a smallest unit of matter which could behave as one molecule. According to this definition, our subject may be changed from the molecular design of network polymer to the molecular design of NPP based on the free-radical crosslinking multivinyl polymerization mechanism. Then, we could construct a variety of CSMs utilizing designed NPP modules. A variety of CSM constructions are exemplified.

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An SEC/MALS study of alternan degradation during size-exclusion chromatographic analysis

2009

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Ultrahigh-molar-mass (M) polymers such as DNA, cellulose, and polyolefins are routinely analyzed using size-exclusion chromatography (SEC) to obtain molar mass averages, distributions, and architectural information. It has long been contended that high-M polymers can degrade during SEC analysis; if true, the inaccurate molar mass information obtained can adversely affect decisions regarding processing and end-use properties of the macromolecules. However, most evidence to the effect of degradation has been circumstantial and open to alternative interpretation. For example, the shift in SEC elution volume as a function of increased chromatographic flow rate, observed using only a concentration-sensitive detector, may be the result of degradation or of elution via a nondegradatory slalom chromatography mechanism. Here, using both concentration-sensitive and multiangle static light-scattering detection, we provide unambiguous evidence that the polysaccharide alternan actually degrades during SEC analysis. The decrease in molar mass and size of alternan with increasing flow rate, measured using light scattering, allows ruling out an SC mode of elution and can only be interpreted as due to degradation. These findings demonstrate the extreme fragility of ultrahigh-M polymers and the care that must be taken for accurate characterization.

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Influence of structural parameters on the degradation of ultrahigh‐molecular‐weight vinyl‐type network‐polymer precursors during elution through size exclusion chromatography columns

Cited by 5 publications

References 17 publications

Mechanistic discussion of cationic crosslinking copolymerizations of 1,2‐epoxycyclohexane with diepoxide crosslinkers accompanied by intramolecular and intermolecular chain transfer reactions

Mechanistic discussion of cationic crosslinking copolymerizations of 1,2‐epoxycyclohexane with diepoxide crosslinkers accompanied by intramolecular and intermolecular chain transfer reactions

Construction of Crosslink‐System‐Materials Utilizing Designed Network‐Polymer‐Precursor Modules

An SEC/MALS study of alternan degradation during size-exclusion chromatographic analysis

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