Carbon-13 and Proton Nuclear Magnetic Resonance Studies of Cellulose Nitrates

Wu, Ting Kai

doi:10.1021/ma60073a015

Cited by 67 publications

(27 citation statements)

References 4 publications

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“…As mentioned earlier, although each anhydroglucose unit contains three hydroxyl groups, the ACHT molecules might mainly bind to the primary hydroxyl groups at C6 because of the difference in reactivity of the hydroxyl groups [53]. Based on these results, the preparation and probable structure of ACHT-immobilized cotton cellulose could be illustrated in Scheme 2.…”

Section: Immobilization Of Acht Onto Cotton Cellulosementioning

confidence: 81%

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Biocidal efficacy, biofilm-controlling function, and controlled release effect of chloromelamine-based bioresponsive fibrous materials

2007

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In this study, 2-amino-4-chloro-6-hydroxy-s-triazine (ACHT) was synthesized through controlled hydrolysis of 2-amino-4,6-dichloro-s-triazine (ADCT). A simple paddry-cure approach was employed to immobilize ACHT onto cellulosic fibrous materials. After treatment with diluted chlorine bleach, the covalently bound ACHT moieties were transformed into chloromelamines. The structures of the samples were fully characterized with NMR, UV/VIS, DSC, TG, iodometric titration and elemental analyses. The chloromelamine-based fibrous materials provided potent, durable, and rechargeable biocidal functions against bacteria (including multi-drug resistant species), yeasts, viruses, and bacterial spores. SEM studies demonstrated that the new fibrous materials could effectively prevent the formation of biofilms, and controlled release investigations in vitro suggested that the biocidal activities were bioresponsive. Biocidal mechanisms of the chloromelamine-based fibrous materials were further discussed.

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Section: Immobilization Of Acht Onto Cotton Cellulosementioning

confidence: 81%

“…These findings suggested that the esterification reactions mainly took place at the primary hydroxyl groups at C6. This was reasonable because the hydroxyl group at C6 was much more reactive than those at C2 and C3 due to steric effects [51][52][53].…”

Section: Immobilization Of Acht Onto Cotton Cellulosementioning

confidence: 92%

Biocidal efficacy, biofilm-controlling function, and controlled release effect of chloromelamine-based bioresponsive fibrous materials

2007

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“…Peak Assignment in 13 C{ 1 H} NMR Spectra of Cellulose Xanthate Figure 2 shows typical 13 C{ 1 H} NMR spectrum of whole region (a) and magnified spectra of substituent peak region (b) and of glucose ring carbon region (c) of the 5 hour's ripened xanthate solution obtained by the liquid-liquid reaction. Twenty peaks, numbered as 1-20 from lower magnetic field, are detected in the range 270-60 ppm.…”

Section: Resultsmentioning

confidence: 99%

“…1 H NMR spectrum can be recorded in a very short time (3-100 s), compared with chemical analysis, but the resolution of NMR peaks is not sufficiently high and also peaks overlap heavily with large water proton signals. In contrast to this, 13 e NMR is a very convenient tool for analyzing the change in of ex in viscose solution as a function of ripening time.…”

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confidence: 99%

13C NMR Study on the Distribution of Substituent Groups on Trihydric Alcohol Units in Cellulose Xanthate

Kamide¹,

Kowsaka²,

Okajima³

1987

Polym J

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ABSTRACT:An attempt was made to investigate 13 C{ 1 H} NMR spectra for cellulose xanthate (CX) in sodium hydroxideiD 2 0 mixture and to assign NMR peaks of CX by applying the DEPT method and by inspecting the change in NMR spectra with ripening time. Based on NMR analysis a direct method is proposed for determining the probability of substitution at hydroxyl groups located at C 2 , C 3 , and C6 positions in trihydric glucopyranose unit (k=2, 3, and 6). The difference in ((fk)) between CXs prepared by the gas-solid (heterogeneous) and liquid-liquid (homogeneous) reactions was also examined. For the latter reactions an alkali-soluble cellulose was employed as starting material. As results, the substitution at C2 and C3 positions was greatly enhanced by the gas-solid reaction and the substitution at C6 was preferential in the liquid-liquid reaction. During ripening, xanthate groups at C2 and C3 positions decomposed first and after complete decomposition of these groups xanthate group at C6 position decomposes very gradually.

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“…Wu, 12 Clark and Stephenson, 13 and Miyamoto et al 14 estimated, from NMR spectra, <(fk)) of cellulose nitrate and CA.…”

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confidence: 99%

Two-Dimensional Nuclear Magnetic Resonance Spectra of Cellulose and Cellulose Triacetate

Kowsaka¹,

Okajima²,

Kamide³

1988

Polym J

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ABSTRACT:An attempt was made to give a full assignment, using only NMR information, to all peaks in 1 Hand 13 C NMR spectra for systems of cellulose in 2.5 N NaOD/D2O and of cellulose triacetate (CTA, total degree of substitution 2.92) in deuterated trichloromethane (TCM-d), and in deuterated dimethylsulfoxide (DMSO-d6). For this purpose two-dimensional (2D) homonuclear 1 H shift correlation spectroscopy (COSY), heteronuclear 1 H-13 C shift correlation spectroscopy (C-H COSY), and long-range heteronuclear 1 H-13 C shift correlation spectroscopy (long-range C-H COSY) were applied to the above systems. By COSY 1 H peaks of cellulose/aq. alkali solution were assigned, from lower magnetic field, to H,, H6 , H6 ', (H3 + H4 + H5), and H2 protons, respectively.Here, two unequivalent H6 peaks heavily overlapped in the one-dimensional spectrum were observed very separately in 2D spectrum. By C-H COSY 13 C peaks of cellulose were assigned, from lower magnetic field, to C1, (C3, C4 , C5), C2 , and C6 carbons, respectively. C3 , C4 , and C5 carbon peaks were unable to be assigned separately, due to mutual and heavy overlapping of H3 , H4 , and H5 peaks. For cellulose triacetate, through use of COSY and C-H COSY all peaks in the region of glucopyranose backbone in 1 H and 13 C NMR wre able to be successfully and completely assigned. Long-range C-H COSY confirmed definitely the existence of the close correlationships between acetyl methyl proton and carbonyl carbon at the different carbon positions of CTA, which showed again the validity of the previous assignment with respect to carbonyl carbons (i.e., C6 , C3 , and C2 carbons from lower magnetic field). KEY WORDSCellulose / Cellulose Acetate / Cellulose Triacetate / 13 C NMR / 1 H NMR / Two-Dimensional NMR / Correlation Spectroscopy/ Long-Range Heteronuclear Correlation Spectroscopy/ Recently numerous studies have been published on the high resolution NMR spectra of solutim1.s of cellulose and its derivatives. NMR spectra of cellulose were utilized widely as a method for elucidating the dissolved state of solutes in solvents (i.e., interaction between solutes and solvents) and those of cellulose derivatives were employed for analysis of the average degree of substitution for each three hydroxyl groups «:fk» (k =2, 3, 6) in the glucopyranose unit: For example, Kamide et a/. 1 showed, from 1 H NMR spectra of eellulose in dimethylformamide/chloral/pyridine mixture, that cellulose dissolved in the form of cellulose trichlorate (CTC) in the solution. Gagnaire and his coworkers 2 speculated the dissolved state of cellulose in Nmethylmorpholine-N-Oxide/dimethylsulfoxide (DMSO), methylamine/DMSO, hydrazine/ DMSO, and paraformaldehyde/DMSO by comparing the 13 C chemical shifts in these solutions. Kamide and his collaborators 3 showed that a physically treated cellulose, whose intramolecular hydrogen bondings were de-* To whom all correspondence should be addressed. 1091

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Carbon-13 and Proton Nuclear Magnetic Resonance Studies of Cellulose Nitrates

Cited by 67 publications

References 4 publications

Biocidal efficacy, biofilm-controlling function, and controlled release effect of chloromelamine-based bioresponsive fibrous materials

Biocidal efficacy, biofilm-controlling function, and controlled release effect of chloromelamine-based bioresponsive fibrous materials

13C NMR Study on the Distribution of Substituent Groups on Trihydric Alcohol Units in Cellulose Xanthate

Two-Dimensional Nuclear Magnetic Resonance Spectra of Cellulose and Cellulose Triacetate

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