Letters to the Editor

Davidson, G. F.; Standing, H. A.; Kornreich, E.

doi:10.1080/19447027.1951.10750262

Cited by 16 publications

(5 citation statements)

References 1 publication

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“…Loss in weight by periodate cellulose in chlorous acid (6), was not necessarily due to chlorite. Davidson and Standing (7) found that chlorite-treated periodate cellulose, after a short time in hot water, lost carboxyl groups and increased in fluidity and copper number. Also, Rutherford el al.…”

Section: Evaluation Of Chlorite Methodsmentioning

confidence: 99%

Failure of Alkaline Methods to Measure Degree of Polymerization of Carbohydrates. Comparison with Chlorite Method

Launer¹,

Tomimatsu²

1961

Anal. Chem.

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Section: Evaluation Of Chlorite Methodsmentioning

confidence: 99%

Failure of Alkaline Methods to Measure Degree of Polymerization of Carbohydrates. Comparison with Chlorite Method

Launer¹,

Tomimatsu²

1961

Anal. Chem.

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“…chain scission and formation of CI aldehydes (Refs. 18,19). This e f k t increases with temperature and moisture and occurs in the aging process when the samples are entered wet into the oven and the temperature is raised to above 100°C.…”

Section: Stability Of Modified Cellulose On Aging and Storagementioning

confidence: 99%

“…The formation of the anhydride linkages was believed to decrease the hot alkali solubility of hydrmlluloses (Ref. 19). These linkages are stable under dry aging conditions and thus the contribution of the Cl aldehydes to the.…”

Section: Stability Of Modified Cellulose On Aging and Storagementioning

confidence: 99%

Oxidation and aging of cellulose

Lewin

1997

Macromolecular Symposia

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Oxidation of cellulose by chlorine, bromine, hydrogen peroxide and ozone and the functional groups formed are reviewed. The roles ofthe pH and of the nature of the oxidant in the formation of carboxy-and ketocelluloses are discussed. The relationships between the functional groups, degradation and stability of the celluloses enable to predict the aging and storage behavior of the polymer. The "active" carbonyls are responsible for the peeling reaction and the formation of the yellow chromophore in alkaline solutions as well as for the reversion in color on aging. The M~U R of the yellow chromophore, its spectra at several pH values, its use for the characterization of cellulose, e.g. the rapid determination of the degree of polymerization and for the estimation of the primary and secondary degradation of the polymer and its stability on storage and aging are d i d . The parallelism between the yellowing and the reversion in color is reviewed. ALKALINE DEGRADATION -THE PEELING REACTIONOxidized cellulose containing the electronegative aldehyde and ketone groups which are in position beta to the glucosidic linkage, are susceptible, according to the beta-alkoxyl elimination mechanism, to chain cleavage. This can be seen in Fig. 2 for celldoses containing a Cg aldehyde or a C2 and a C3 ketone. (Ref. 7). In the case of a C, aldehyde group, (as in the case of hydmcelldose) which is in position gamma to the glycoxyl group, a Lobryde Bryun-Van Eckenstam transformation takes place by which an enediol of C1 and C2 is formed, which is then converted to the Cz ketose, being beta to the glycoxyl group, which enables the elimination of another monomeric double-bond containing monosaccharide (see Fig. 3). This depolymerization process, known as the "peeling" reaction, will continue until the whole length of the chain located in the less ordered regions (LOR) of the polymer will be depolymerized, or until a stopping reaction sets in, in which metasaccharinic end groups are formed.

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“…It is known [ 11,12,38] that carboxyl-containing cellulose is hydrolyzed upon storage under the influence of hydrogen ions derived from the carboxyl groups. The rate of this autohydrolysis increases with the increase in temperature and moisture content of the samples and can be almost stopped at 0°C or complete dryness of the samples.…”

Section: Autohydrolysismentioning

confidence: 99%

The Yellowing of Cotton Cellulose

Lewin

1965

Textile Research Journal

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The differences between the brightness reversion on aging and the yellowing in alkaline solution found for hydrocelluloses and carboxyl-containing celluloses are explained by anhydridization of the terminal C 1 aldehydes on aging and autohydrolysis caused by the carboxyl groups. The reaction sequence leading to the formation of the yellow substances seems to involve a peeling-off of glucose units from the chain ends, isomerization and fragmentation of the peeled glucose units, and condensation of the fragments to furan derivatives and to carbonyl-groups-containing colored substances. The smaller contribution to yellowing of the aldehydes in NaClO-oxidized cottons, as compared to hydrolyzed cotton, is explained by postulating the existence of "inactive" aldehydes which do not cause peeling. The possible reasons for the lack of yellowing of keto-celluloses are discussed.,

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Letters to the Editor

Cited by 16 publications

References 1 publication

Failure of Alkaline Methods to Measure Degree of Polymerization of Carbohydrates. Comparison with Chlorite Method

Failure of Alkaline Methods to Measure Degree of Polymerization of Carbohydrates. Comparison with Chlorite Method

Oxidation and aging of cellulose

The Yellowing of Cotton Cellulose

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