Ethylenediamine‐induced conversion of cellulose I to cellulose III

Lokhande, H. T.; Shukla, S. R.; Chidambareswaran, P. K.; Patil, N. B.

doi:10.1002/pol.1977.130150207

Cited by 18 publications

(19 citation statements)

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“…Four cycles of swelling-methanol washingdrying were repeated in order to ensure full conversion of cellulose I to cellulose 111. 5 The results indicate that the conversion of cellulose I into cellulose I11 is the highest, giving the LCR value of 1.28 for a sample treated with 100% EDA alone. The LCR decreases with the decrease in the proportion of pure EDA and the corresponding increase in the amount of morpholine in the EDA-morpholine mixtures and it is the least at 0.48 for a sample treated with 30:'ZO EDA:morpholine mixture.…”

Section: Proportions Of Morpholine (A) and Ethylenediamine (B)%(wavhn)mentioning

confidence: 93%

Swelling of cotton fibers in ethylenediamine–morpholine mixtures

Lokhande

Sirmour

Shukla

et al. 1984

J of Applied Polymer Sci

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SynopsisCotton fibers were treated with anhydrous mixtures of ethylenediamine and morpholine of varying proportions to study the changes in accessibility (X-ray crystallinity index, swelling by propanol-2 retention, formylation, and dyeability) as well as lattice conversions from cellulose I to cellulose I1 and cellulose 111. Positive synergistic influence of the highest order was noticed at 7030 (molar proportion 31) ethylenediamine-morpholine mixture as judged from accessibility and lattice conversion from cellulose I to cellulose 11. The same critical proportion was found to give the highest order of negative synergistic effect in the lattice conversion of cellulose I into cellulose 111. These opposing trends have been explained on the basis of t h e different mechanisms associated with the lattice conversions of cellulose I into cellulose I1 and cellulose 111.

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Section: Proportions Of Morpholine (A) and Ethylenediamine (B)%(wavhn)mentioning

confidence: 93%

Swelling of cotton fibers in ethylenediamine–morpholine mixtures

Lokhande

Sirmour

Shukla

et al. 1984

J of Applied Polymer Sci

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“…Thc conversion to cellulose Ill1 was accomplished by swelling the fibers in 75% aqueous cthylcnc diamine for 5 h at 35°C. followcd by washing with anhydrous methanol (8). The process was repeated three times.…”

Section: Methodsmentioning

confidence: 99%

Packing analysis of carbohydrates and polysaccharides. 16. The crystal structures of celluloses IV_I and IV_II

Gardiner¹,

Sarko²

1985

Can. J. Chem.

102

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This paper is dedicated to the IOtll tmniverstrry of the Xeroa Resetrrrh Centre of' Conclda ERIC S. GARDINER and ANATOLE SARKO. Can. J. Chem. 63, 173 (1985). The crystal structures of cellulose polymorphs IV, and lV11 have been dctermincd by X-ray fiber diffraction analysis combined with stereochemical model refinement. Both structures crystallize in a two-chain unit cell of essentially identical parameters. The most probable space group in both cases is P I . Thc chain conformations, although close to two-fold helical, are marked by unequal rotational positions of the O(6) hydroxyl groups in adjacent rcsiducs. Despite identical unit cell parameters, the structures differ in chain polarity: in cellulose IVI both chains of thc unit cell are parallel, whcreas in cellulosc IV,, they are antiparallel. The difference in polarlty is further substantiated by the results of chemical conversions which show that cellulose IV, is converted to cellulosc I, and cellulosc IV,, is converted to cellulosc 11. via parallel and antiparallel cellulose triacetates, respectively. The reliability of the structure analyses is indicated by the residual R" = 0.1 15 for cellulose IV, and 0.094 for cellulose IVII, for data sets of 41 and 43 reflections. respectively. ERIC S. GARDINER et ANATOLE SARKO. Can. J . Chem. 63, 173 (1985). Faisant appel h unc analysc de la diffraction dcs rayons-X par les fibres combinee avec une affinement du modklc stCrCochimique, on a determine les structures cristallines des polymorphcs IVI ct IV,, dc la cellulose. Lcs deux structures cristallisent dans une cellule unitaire ii deux chaincs ct Ics parametres dc chacunc de ccs cellules sont cssentiellement idcntiques. Dans chacun des cas, le groupe d'espace le plus probablc est P I . Les conformations des chaines sont pratiquement toutes les deux sous formes d'hklices binaires; toutcfois, les groupes hydroxyles en (0)6 des risidus adjacents sont dans dcs positions rotationnelles diff6rcntes. MEme si les parametres de la cellule unitaire sont identiques, la polaritt des chaines differc suivant les structures: dans la cellulose IV,, les deux chaines dc I'unite cellulaires sont parallklcs alors que dans la cellulose IV,, elks sont antiparallkles. La difference de polarit6 est confirm& par les rksultats de conversions chimiques qui montrent quc la cellulose IV, pcut &tre transform& en cellulose I et la ccllulosc IV,, est transformkc cn ccllulosc 11 par le biais dc triacitatcs dc cellulose qui sont respectivcment parallklcs et antiparallkles. La fiabilitk dcs analyses structurales cst indiquCc par Ics valeurs de R" qui sont 0,115 et 0,094 repectivement pour Ics celluloscs IV, ct IVI, ct qui sont baskcs sur des ensembles de donnCcs de 41 et 43 rkflexions.[Traduit par le journal]

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“…The major difference between 4 cellulose III and cellulose I is that in cellulose III the chains are not aligned as flat stacking sheets with van der Waals bonding in between but as conjugated sheets with zig-zagging hydrogen bonding between them. [38][39][40] This is caused by the primary alcohol rotating into a gauge-trans position from the trans-gauge position during the introduction of the guest molecule into the crystal 39,[41][42][43][44] or -as proposed recently -proton hopping from one hydroxyl group to the other. 45 When the host molecule is removed by rinsing with methanol or ethanol, the gauge-trans position remains in the resulting cellulose III structure (Figure 1).…”

Section: Introductionmentioning

confidence: 99%

“…Cellulose I was transformed into cellulose III by dispersing the CNCs into 75 % aqueous ethylenediamine (EDA) solution for 5 h at 35 °C, after which the EDA solution was decanted and the CNCs immersed in anhydrous methanol. 43 The methanol was decanted off and replaced with fresh anhydrous methanol. The washing step was repeated several times.…”

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confidence: 99%

“…1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 The polymorphic transition of CNCs in dispersion (Figure 2a) was followed by solid state nuclear magnetic resonance spectroscopy ( 13 C NMR). The conversion from cellulose I to III was performed by first preparing the EDA-cellulose complex from freeze dried CNCs and rinsing the EDA away with methanol -altogether an established procedure for cellulosic fibers 43 but not previously reported for CNCs. This change to cellulose III in bulk dispersion was determined with 13 C MAS NMR both using Cross Polarization (CP) ( Figure S3) and single pulse (SP) (Figure 4 and S2), the latter being used as a complement for CP experiments, more sensitive but known to be not quantitative.…”

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Surface-Induced Frustration in Solid State Polymorphic Transition of Native Cellulose Nanocrystals

2017

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ABSTRACT. The presence of an interface generally influences crystallization of polymers from melt or from solution. Here, by contrast, we explore the effect of surface immobilization in a direct solid state polymorphic transition on individual cellulose nanocrystals (CNCs), extracted from a plant-based origin. The conversion from native cellulose I to cellulose III crystal occurred via a 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 2 host-guest inclusion of ethylene diamine inside the crystal. 60% reduction in CNC width (height) in atomic force microscopy images suggested that when immobilized on a flat modified silica surface, the stresses caused by the inclusion or the subsequent regeneration resulted in exfoliation, hypothetically between the van der Waals bonded sheets within the crystal. Virtually no changes in dimensions were visible when the polymorphic transition was performed to non-immobilized CNCs in bulk dispersion. With reservations and by acknowledging the obvious dissimilarities, the exfoliation of cellulose crystal sheets can be viewed as analogous to exfoliation of 2D structures like graphene from a van der Waals stacked solid. Here, the detachment is triggered by an inclusion of a guest molecule inside a host cellulose crystal and the stresses caused by the firm attachment of the CNC on a solid substrate, leading to detachment of molecular sheets or stacks of sheets.

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Ethylenediamine‐induced conversion of cellulose I to cellulose III

Cited by 18 publications

References 5 publications

Swelling of cotton fibers in ethylenediamine–morpholine mixtures

Swelling of cotton fibers in ethylenediamine–morpholine mixtures

Packing analysis of carbohydrates and polysaccharides. 16. The crystal structures of celluloses IV_I and IV_II

Surface-Induced Frustration in Solid State Polymorphic Transition of Native Cellulose Nanocrystals

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Ethylenediamine‐induced conversion of cellulose I to cellulose III

Cited by 18 publications

References 5 publications

Swelling of cotton fibers in ethylenediamine–morpholine mixtures

Swelling of cotton fibers in ethylenediamine–morpholine mixtures

Packing analysis of carbohydrates and polysaccharides. 16. The crystal structures of celluloses IVI and IVII

Surface-Induced Frustration in Solid State Polymorphic Transition of Native Cellulose Nanocrystals

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Product

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Packing analysis of carbohydrates and polysaccharides. 16. The crystal structures of celluloses IV_I and IV_II