Carbon‐13 NMR of hydroxyethylcellulose: An accurate method for structural determination

DeMember, John R.; Taylor, Lloyd D.; Trummer, Steven; Rubin, Leon E.; Chiklis, Charles K.

doi:10.1002/app.1977.070210304

Cited by 35 publications

(15 citation statements)

References 9 publications

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“…The molar substitution (MS = 0.58) valued of the HEC sample were determined from the 1 H NMR spectra, quantifying the peak areas from 3.5 to 4.4 ppm and from 4.3 to 5.8 ppm. 6,7 The degrees of substitution (DS = 0.34) were obtained from MS results and the peak areas at 69.7 and 60.0 ppm in the corresponding 13 C NMR spectra. 7,8 The weight average degree of polymerization (DP = 850) was determined through the Mark± Houwinck±Sakurada equation (K = 1.1 Â 10 À2 and a = 0.87) 7,9 using intrinsic viscosity values determined with a capillary viscometer.…”

Section: Methodsmentioning

confidence: 99%

DSC and solid state NMR characterization of hydroxyethylcellulose/polyether films

Regiani¹,

Tambelli²,

Pawlicka³

et al. 2000

Polym. Int.

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Section: Methodsmentioning

confidence: 99%

DSC and solid state NMR characterization of hydroxyethylcellulose/polyether films

Regiani¹,

Tambelli²,

Pawlicka³

et al. 2000

Polym. Int.

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“…Although NMR has been utilized extensively for compositional analysis as well as structural characterization of polymers (12,13), its application to industrial cellulosic polymers has been rather limited (14)(15)(16)(17)(18). This limitation results primarily from the relatively low solubility and high viscosity of solutions of these materials used for NMR analysis.…”

Section: Resultsmentioning

confidence: 99%

Proton nuclear magnetic resonance spectrometry for determination of substituents and their distribution in carboxymethylcellulose

Ho¹,

Klosiewicz²

1980

Anal. Chem.

137

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Carboxymethylcellulose (CMC) was hydrolyzed in aqueous sulfuric acid at -90 OC to yield substituted glucoses which were analyzed by proton nuclear magnetic resonance. A procedure for the measurement of the degree of substitution (DS) of CMC was developed. Agreement of the DS determlned in thls procedure with that obtalned from a standard ASTM method is generally good. Additionally, the average distribution of the carboxymethyl substituents in CMC was also measured from the same spectrum. This result showed that the reactivity of the hydroxyls in cellulose toward carboxymethylation varied in the order OH(2) > OH(6) > OH(3), where the numbers In parentheses represent the carbon posllions in the anhydroglucose unit.Carboxymethylcellulose (CMC) is an important industrial polymer which finds wide application in detergents, textiles, paper, food, drugs, and oil well drilling operations, among others. In 1974, over 75 million pounds were produced in the United States alone ( I ) . Many of the properties of CMC in actual applications depend to a large extent on two key structural parameters, namely, the degree of substitution (DS) of the hydroxyl groups on the anhydroglucose unit and the distribution of the carboxymethyl substituents.A spectrophotometer is described in which a linear photoarray using charge-coupled technology is used as a detector. The device can access 260 nm of the visible spectrum in as little as 8 ms. Using the detector's integrating character, the exposure time is programmed by computer so that the signalto-noise ratio can be substantially Improved. A model for the variance as a function of wavelength and absorbance was developed and validated.

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“…4(a)] permits the , and 46 ppm correspond to the pyrrolidinone group, which further supports the presence of both HEC-and HMP-like species within the isolated material. 28,29 The HMBC experiment [ Fig. 4(b)] highlights the covalent bonding between HMP and HEC.…”

Section: -(Hydroxymethyl)-2-pyrrolidinonementioning

confidence: 99%

Preparation, properties, and antibacterial behavior of a novel cellulose derivative containing lactam groups

Joubert

Sharples

Musa

et al. 2014

J. Polym. Sci. Part A: Polym. Chem.

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Lactam groups were introduced onto the backbone of hydroxyethyl cellulose (HEC) to modify properties, such as solubility in organic solvents and solution viscosity and to introduce possible antibacterial activity. Functionalization was achieved using 1-(hydroxymethyl)-2-pyrrolidinone (HMP), and the functionalization reactions were investigated using NMR spectroscopy. The covalent attachment between HEC and HMP was confirmed using 1 H-13 C correlated NMR experiments. Degrees of functionalization were calculated using integrated 13 C NMR spectra, with values of up to 0.9 being demonstrated on the primary alcohol functionality of HEC. The functionalized HECs showed markedly different properties to unfunctionalized HEC, including the ability to swell considerably in water. Functionalized HEC displayed increased thermal stability and reduced solution viscosity compared with unfunctionalized HEC. Moreover, functionalization altered the bacterial adhesion characteristics compared with unfunctionalized HEC.

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Carbon‐13 NMR of hydroxyethylcellulose: An accurate method for structural determination

Cited by 35 publications

References 9 publications

DSC and solid state NMR characterization of hydroxyethylcellulose/polyether films

DSC and solid state NMR characterization of hydroxyethylcellulose/polyether films

Proton nuclear magnetic resonance spectrometry for determination of substituents and their distribution in carboxymethylcellulose

Preparation, properties, and antibacterial behavior of a novel cellulose derivative containing lactam groups

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