Part I: A New Method for the Determination of Yellowing

Albeck, Michael; Ben-bassat, Albert A.; Epstein, Joseph A.; Lewin, Menachem

doi:10.1177/004051756503500908

Cited by 12 publications

(8 citation statements)

References 8 publications

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“…This figure seems reasonable when compared to the range of P of 65-33 obtained by Samuelson and coworkers under much more drastic conditions. As shown in Figures 3 and 5 of part I of this study [ 2 ] , the color intensity and, therefore, P increases with the concentration of alkali and with the time of extraction. The curves in Figure 5 approach asymptotically a limit ing D value after 6 hr.…”

Section: Autohydrolysissupporting

confidence: 53%

“…The predominant reaction is reaction a), while the relative importance of reaction c) increases with the decrease in the degree of polymerization of the hydrocellulose [6]. It is evident that in the present investigation [2] the formation of the yellow color in the bicarbonate solutions is closely related to the peeling-off reach-tion. The relatively low concentration of the alkali (pH 10.4) and the short duration of the alkaline treatment preclude any significant contribution of the hydrolytic chain cleavage of reaction b) and only the reactions a) and c) occur.…”

Section: Autohydrolysismentioning

confidence: 59%

“…It is of interest to note that the P value obtained by the new method is not dependent on the aldehyde content or the DP of the hydrocellulose, as can be deduced from the straight-line relationships in Figures 5 and 6 in part I of this study [ 3 ] . This indicates that even at relatively low DP values reaction c) has little influence on P. The fact that the curves in Figure 5 of part I of this study [ 2 ) approach asymptotically a constant D value is probably due to the stopping reaction [ 7,8,28,29 ] .…”

Section: Autohydrolysismentioning

confidence: 60%

“…If, however, the carboxy·1-' containing cottons are stored for prolonged periods the autohydrolysis will produce new aldehydes which will increase the yellowing. This might explain at least partly the residual yellowing of samples postoxidized with chlorite [31 and the observed increase in D upon long storage of the samples [2].…”

Section: Autohydrolysismentioning

confidence: 99%

“…In the previous parts of this investigation [2,3 ] evidence was brought forward on the parallelism between the color intensity of the yellow bicarbonate extract of oxidized cottons and the reversion in color on aging as measured by the pc number method. In brief, both values change similarly with the increase in consumed oxygen, in the aldehyde content, with the increase in hot alkali solubility, with the change in pll of the oxidation and, upon post treatments of the oxidized cellulose, with chlorite and borohydride solutions.…”

Section: Introductionmentioning

confidence: 99%

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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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Section: Autohydrolysissupporting

confidence: 53%

Section: Autohydrolysismentioning

confidence: 59%

Section: Autohydrolysismentioning

confidence: 60%

Section: Autohydrolysismentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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The Yellowing of Cotton Cellulose

Lewin

1965

Textile Research Journal

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Understanding paper degradation: identification of products of cellulosic paper decomposition at the wet-dry “tideline” interface using GC-MS

et al. 2016

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Cellulose paper degradation products forming in the "tideline" area at the wet-dry interface of pure cellulose paper were analyzed using gas chromatography-electron ionization-mass spectrometry (GC-EI-MS) and high-resolution electrospray ionization-mass spectrometry (ESI-MS, LTQ Orbitrap) techniques. Different extraction protocols were employed in order to solubilize the products of oxidative cellulose decomposition, i.e., a direct solvent extraction or a more laborious chromophore release and identification (CRI) technique aiming to reveal products responsible for paper discoloration in the tideline area. Several groups of low molecular weight compounds were identified, suggesting a complex pathway of cellulose decomposition in the tidelines formed at the cellulose-water-oxygen interface. Our findings, namely the appearance of a wide range of linear saturated carboxylic acids (from formic to nonanoic), support the oxidative autocatalytic mechanism of decomposition. In addition, the identification of several furanic compounds (which can be, in part, responsible for paper discoloration) plus anhydro carbohydrate derivatives sheds more light on the pathways of cellulose decomposition. Most notably, the mechanisms of tideline formation in the presence of molecular oxygen appear surprisingly similar to pathways of pyrolytic cellulose degradation. More complex chromophore compounds were not detected in this study, thereby revealing a difference between this short-term tideline experiment and longer-term cellulose aging.

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