Acetals and hemiacetals

Schmitz, Ernst; Eichhorn, I.

doi:10.1002/9780470771075.ch7

Cited by 12 publications

(19 citation statements)

References 156 publications

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“…The hemiacetals are easily formed and relatively stable for those aldehydes whose carbonyl group is strongly electron deficient. 20 The dry properties of the paper treated by glyoxal and glutaraldehyde are shown in Table I. The data show no significant change in dry strength after the chemical treatment with both glyoxal and glutaraldehyde.…”

Section: Properties Of the Paper Treated With Dialdehydes Without A Cmentioning

confidence: 98%

“…Glyoxal is able to react with hydroxyl groups of cellulose to form hemiacetal bonds between cellulose molecules. 20 The improved wet strength of the glyoxal-treated paper without curing suggests that the hemiacetals form so easily as the water is removed from the treated paper during the drying process that further curing is not needed. The hemiacetal bonds produced by glyoxal between cellulose molecules, however, are sensitive to water and can be replaced by hemiacetal bonds with water when the paper is saturated by water for a short period of time.…”

Section: Properties Of the Paper Treated With Dialdehydes Without A Cmentioning

confidence: 99%

“…It is well known that aldehyde reacts with the hydroxyl group to form acetal under catalysis of Lewis acids. 20 Acetal is stable under neutral and alkaline conditions. The data show that high curing temperature increases reaction rate and shifts the reaction equilibrium to the direction of acetal formation.…”

Section: Properties Of the Paper Treated With Dialdehydes With Zn(no mentioning

confidence: 99%

“…The acetal formation is strongly affected by steric and conformational factors. 20 As demonstrated in Scheme 1, one glutaraldehyde molecule may react with four cellulose hydroxyl groups by acetalization. For glyoxal, however, the two aldehyde groups are too close to each other to allow them to reach cellulosic hydroxyl groups to form crosslinkages.…”

Section: Properties Of the Paper Treated With Dialdehydes With Zn(no mentioning

confidence: 99%

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Applications of bifunctional aldehydes to improve paper wet strength

Yang

Deng³

2002

J of Applied Polymer Sci

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Glyoxal and glutaraldehyde behave very differently for improving wet strength of paper. It is found that glyoxal is very efficient for improving temporary wet strength of paper without the presence of a catalyst and exposure to elevated temperatures. When a metal salt, such as Zn(NO 3 ) 2 , is used as a catalyst and the curing temperature is increased, the durable wet strength of glyoxal-treated paper increases at the expense of its flexibility, as shown by reduced stretch and folding endurance. Glutaraldehyde is not able to provide any improvement in wet strength to paper, even under high curing temperatures, provided no catalyst is used. With the aid of a metal salt catalyst, glutaraldehyde imparts excellent durable wet strength to paper without significantly sacrificing folding endurance, and the wet strength of glutaraldehydetreated paper increases steadily as curing temperature increases. The different behavior of glyoxal and glutaraldehyde may be attributed to their different reactivity toward cellulose.

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Section: Properties Of the Paper Treated With Dialdehydes Without A Cmentioning

confidence: 98%

Section: Properties Of the Paper Treated With Dialdehydes Without A Cmentioning

confidence: 99%

Section: Properties Of the Paper Treated With Dialdehydes With Zn(no mentioning

confidence: 99%

Section: Properties Of the Paper Treated With Dialdehydes With Zn(no mentioning

confidence: 99%

See 2 more Smart Citations

Applications of bifunctional aldehydes to improve paper wet strength

Yang

Deng³

2002

J of Applied Polymer Sci

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“…Higher temperatures achieved greater permanent wet strength. It may be that higher curing temperatures increase the acetal reaction between glyoxal and the hydroxyl groups of cellulose molecules under the catalysis of Lewis acids, which would result in handsheets with better wet strength performance (Schmitz and Eichhorn 1967). …”

Section: Wet Strength Of Handsheets Treated With Glyoxalmentioning

confidence: 99%

Combination of Glyoxal and Chitosan as the Crosslinking System to Improve Paper Wet Strength

Zhang¹,

Zhang²,

Song³

et al. 2013

BioResources

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The wet strength of handsheets subjected to dipping treatment by solutions such as glyoxal with Zn(NO 3 ) 2 as a catalyst, chitosan, and the crosslinking system of glyoxal and chitosan is studied in this paper. The crosslinking system achieved better wet strength performance than glyoxal or chitosan alone and slightly better than the sum of glyoxal and chitosan in the case of a curing temperature between 90 and 130 o C. However, handsheets treated by this crosslinking system became more brittle, which was shown by the reduction of folding endurance of the handsheets with increasing wet strength. The capillary rise and contact angle of the treated handsheets showed certain relations to their wet strength when the above solutions were used to improve the wet strength of the handsheets. The physical changes of the treated handsheets can provide evidence to explain the mechanism of wet strength development.

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Intramolecular Reversible Addition Reactions to the C=O Group

Valters¹,

Flitsch

1985

Ring-Chain Tautomerism

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Acetals and hemiacetals

Cited by 12 publications

References 156 publications

Applications of bifunctional aldehydes to improve paper wet strength

Applications of bifunctional aldehydes to improve paper wet strength

Combination of Glyoxal and Chitosan as the Crosslinking System to Improve Paper Wet Strength

Intramolecular Reversible Addition Reactions to the C=O Group

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