Molecular Weight Distribution of Cellulose by On-Line Size Exclusion Chromatography — Low Angle Laser Light Scattering Part I: Basic Experiments and Treatment of Data

Lauriol, Jean-Marc; Froment, Pierre; Pla, Fernand; Robert, André

doi:10.1515/hfsg.1987.41.2.109

Cited by 45 publications

(54 citation statements)

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“…11 explains why MarxFigini (1986) still obtained a downward curvature of the kinetic plots after removing the weak links with an initial pre-hydrolysis. Moreover, the presence of weak links which degrade ad higher rate should cause an increase of the polydispersity (DP w /DP n ) of the distribution of molecular weights, as found by Lauriol et al (1987) with Size Exclusion Chromatography.…”

Section: Hydrolytic Degradationmentioning

confidence: 93%

“…The recursive application of Eq. 11 (weak links plus glycosidic bonds in the amorphous regions; amorphous regions alone; amorphous plus crystalline regions) indicates that the contribute of weak links is negligible, while either the degradation of amorphous regions alone or the degradation of amorphous plus crystalline regions Daruwalla and Narsian (1966); b, Lauriol et al (1987); c, Nelson and Tripp (1953) Cellulose (2008) 15: 193-203 197 result in a good fit of the experimental data (Figs. 5,6).…”

Section: Oven Ageingmentioning

confidence: 99%

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On the kinetics of cellulose degradation: looking beyond the pseudo zero order rate equation

2007

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The kinetics of cellulose degradation was analysed by means of a two-stage model, characterised by an autoretardant and autocatalytic regime, later tempered by the consumption of glycosidic bonds in the amorphous regions. The proposed model explains the effects on the kinetic equations of different modes of ageing (acid hydrolysis, ageing in ventilated oven or sealed vessels), initial oxidation of cellulose and experimental procedures (with or without reduction of oxidised groups). The autoretardant branch can be analysed in a quantitative way, while the integration of the non-linear autocatalytic branch is allowed in some cases, characterised by the decrease of pH and/or emission of acid volatile organic compounds (VOCs). Most of the controversial results of the literature can be easily explained, but the proposed model offers also a guide for further studies on the kinetics of cellulose degradation.

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Section: Hydrolytic Degradationmentioning

confidence: 93%

Section: Oven Ageingmentioning

confidence: 99%

On the kinetics of cellulose degradation: looking beyond the pseudo zero order rate equation

2007

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“…In most protocols DMSO was used as the derivatization solvent, sometimes pyridine, or mixtures of both solvents. On the one hand, cellulose degradation was found to be more pronounced in DMSO (Lauriol et al 1987;Evans et al 1991a), but on the other hand, DMSO proved to be superior as reaction medium with regard to faster and better dissolution and shorter overall reaction times. The degradation in DMSO was assumed to be due to an oxidizing effect of the solvent in combination with isocyanate, similar to Moffatt oxidation systems (Pfitzner and Moffatt 1963;Moffatt 1971), which would introduce carbonyl structures that subsequently cause chain cleavage according to b-elimination mechanisms (Fischer 2005, Fischer andFischer 2005).…”

mentioning

confidence: 97%

“…A reliable derivatization without degradation (polymer-analogous derivatization) thus could not be performed so far. Many derivatization procedures for cellulose tricarbanilates have been reported (Hall and Horne 1973;Valtasaari and Saarela 1975;Schroeder and Haigh 1979;Wood et al 1986;Lauriol et al 1987;Evans et al 1989Evans et al , 1991aTerbojevich et al 1995). In most protocols DMSO was used as the derivatization solvent, sometimes pyridine, or mixtures of both solvents.…”

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confidence: 99%

Studies on DMSO-containing carbanilation mixtures: chemistry, oxidations and cellulose integrity

et al. 2007

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The oxidative effect of carbanilation mixtures containing dimethylsulfoxide (DMSO) was demonstrated by means of alcohol model substances in which competitive carbanilation was prevented due to steric hindrance of the hydroxyl function, rendering those compounds specific probes for oxidation effects. Dimethylsulfonium ions and derived ylide species were shown to be the actually oxidizing species according to trapping methodology using lipophilic olefins which were converted into the corresponding cyclopropane and epoxide derivatives. The experimental data were in good agreement with DFT computations carried out on the B3LYP/6-311+G(d,p) level of theory. The direct interaction of cellulose and sulfoxide solvent was proven by means of methyl-(2-naphthyl)sulfoxide (MNSO) as a model for DMSO, which caused introduction of UV-detectable methylthionaphthyl ether moieties into the cellulose, formed in Pummerer-type side reaction paralleling the chemical behavior of DMSO. A facile color test-responding to sulfoxide-derived oxidizing species-was developed to assess the suitability of carbanilation conditions with regard to cellulose oxidation and degradation. DMSO-based carbanilation systems have to be used with great caution for determination of molecular weight parameters and for similar purposes which require complete maintenance of the cellulose integrity. Cellulose oxidation/ degradation by DMSO-derived intermediates upon carbanilation can be minimized but cannot be avoided completely. Thus, if cellulose integrity is an issue as it is in cellulose analytics, it is recommended to replace DMSO by solvent components of similar solution behavior but without the inherent danger of generating oxidants, such as pyridine or DMAc, whenever possible.

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“…and zeolite were first defibred in a beaker in 50 cm 3 of water (the process was aided by ultrasound waves). The standard procedure of preparing cellulose material was applied (Lauriol et al 1987;Stol et al 2002), using cellulose derivative CTC in THF solution. The AgFAU was removed from the CTC solutions by filtration through a Teflon syringe filter with pore diameter of 0.45 lm.…”

Section: Degree Of Polymerisationmentioning

confidence: 99%

Paper material containing Ag cations immobilised in faujasite: synthesis, characterisation and antibacterial effects

et al. 2017

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The study is devoted to manufacturing and characterising a new paper material with antimicrobial properties, as an alternative to paper containing silver nanoparticles (NPs) which are claimed to be harmful to the ecosphere. In place of silver NPs, the new material contains faujasite mineral (from the faujasite group) exchanged with silver cations which are firmly attached to the material's lattice. The material was obtained by typical ion exchange and additional elution with EDTA salt to dispose of the remaining silver oxide NPs. Thus, modified faujasite was then added to paper pulp. The new, modified paper showed better quality in terms of acidity, tensile strength and cellulose degree of polymerisation compared to paper containing Ag NPs. The visual quality of the paper is also better than that containing Ag NPs. The new material shows high potential for use in food and pharmaceutics packaging.

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Molecular Weight Distribution of Cellulose by On-Line Size Exclusion Chromatography — Low Angle Laser Light Scattering Part I: Basic Experiments and Treatment of Data

Cited by 45 publications

References 1 publication

On the kinetics of cellulose degradation: looking beyond the pseudo zero order rate equation

On the kinetics of cellulose degradation: looking beyond the pseudo zero order rate equation

Studies on DMSO-containing carbanilation mixtures: chemistry, oxidations and cellulose integrity

Paper material containing Ag cations immobilised in faujasite: synthesis, characterisation and antibacterial effects

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