Characterization of tri-o-methylcellulose by one- and two-dimensional NMR methods

Sachinvala, Navzer D.; Hamed, Othman; Winsor, David L.; Niemczura, Walter P.; Maskos, Karol; Parikh, D. V.; Glasser, Wolfgang G.; Becker, Ulli; Blanchard, Eugene J.; Bertoniere, Noelie R.

doi:10.1002/(sici)1099-0518(19991101)37:21<4019::aid-pola16>3.0.co;2-z

Cited by 15 publications

(19 citation statements)

References 39 publications

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“…The molar percentage of ε‐CL grafted onto the polysaccharide can be determined from the ratio between the carbon C 1 of methylcellulose around 102.5 ppm and the carbon C C of poly(ε‐CL) at 28.4 ppm on the quantitative 13 C NMR spectra presented in Figure . Methylcellulose assignments were made based on the literature . This leads to about 90% poly(ε‐CL) in the grafted copolymer.…”

Section: Resultsmentioning

confidence: 99%

Brønsted acid-catalyzed polymerization of ε-caprolactone in water: A mild and straightforward route to poly(ε-caprolactone)-graft -water-soluble polysaccharides

Stanley

Bucataru

Miao

et al. 2014

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

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The polymerization of e-caprolactone (e-CL) has been assessed in water using various Brïnsted acids as catalysts. The reaction was found to be quantitative at 100 C, leading to number-average molecular weights up to 5000 g mol 21 .The Brïnsted acid-catalyzed polymerization of e-CL in water was further conducted in the presence of water-soluble polysaccharides thereby affording graft copolymers. The approach enables an easy, mild access to dextran hydroxyesters. For low degree of substitution, the latter self-assembles in water to form nanoparticles. Poly(e-CL)-graft-methylcellulose copolymers can also be obtained via a similar approach. It is note-worthy that the methodology reported herein is a one-step route to poly(e-CL)-graft-water-soluble polysaccharides, operating in mild conditions, that is, at low temperatures, using readily available metal-free catalysts and water as a solvent.

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Section: Resultsmentioning

confidence: 99%

Brønsted acid-catalyzed polymerization of ε-caprolactone in water: A mild and straightforward route to poly(ε-caprolactone)-graft -water-soluble polysaccharides

Stanley

Bucataru

Miao

et al. 2014

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

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“…Analysis of the spectra was performed after identification of the different signals according to the literature [25][26][27][28].…”

Section: Methodsmentioning

confidence: 99%

“…The identification of different signals is performed as described previously [25][26][27][28]. Figure 2 shows the 13 C-NMR spectrum of a MC with an average DS (DS = 1.8).…”

Section: Substitution Patternmentioning

confidence: 99%

Methylcellulose, a Cellulose Derivative with Original Physical Properties and Extended Applications

et al. 2015

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This review covers the preparation, characterization, properties, and applications of methylcelluloses (MC). In particular, the influence of different chemical modifications of cellulose (under both heterogeneous and homogeneous conditions) is discussed in relation to the physical properties (solubility, gelation) of the methylcelluloses. The molecular weight (MW) obtained from the viscosity is presented together with the nuclear magnetic resonance (NMR) analysis required for the determination of the degree of methylation. The influence of the molecular weight on the main physical properties of methylcellulose in aqueous solution is analyzed. The interfacial properties are examined together with thermogelation. The surface tension and adsorption at interfaces are described: surface tension in aqueous solution is independent of molecular weight but the adsorption at the solid interface depends on the MW, the higher the MW the thicker the polymeric layer adsorbed. The two-step mechanism of gelation is confirmed and it is shown that the elastic moduli of high temperature gels are not dependent on the molecular weight but only on polymer concentration. Finally, the main applications of MC are listed showing the broad OPEN ACCESSPolymers 2015, 7 778 range of applications of these water soluble cellulose derivatives.

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“…In the search for bio-based materials, polysaccharide derivatives are of continuing interest. Recently, 2-D NMR analyses were used to characterize 2,3,6-tri- O -methyl cellulose to better understand the effects of methylation and derivatization in general.…”

Section: Introductionmentioning

confidence: 99%

Conformational Analyses of Native and Permethylated Disaccharides

et al. 2002

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Effects of permethylation on disaccharide conformation were studied with relaxed-residue φ,ψ maps for eight disaccharides of glucose and their permethylated derivatives. Many orientations of the methyl groups were generated with the conformation generator in the Chem-X software program and filtered with a rules-based method. For native molecules, clockwise and counterclockwise rings of hydrogen bonds were also used. MM3(96) energies were calculated with a dielectric constant ( ) of 1.5. The native disaccharide maps were also calculated at ) 3.5 and 7.5 to reduce hydrogen-bonding strength. Maps for native and permethylated structures were generally similar. The permethylated structures, which do not make hydrogen bonds, gave maps that were most similar to the native maps that had reduced hydrogen-bonding strength. All φ,ψ values for the global minima of the permethylated models fell within the 1-kcal/mol contours on the ) 7.5 maps. Flexibility values based on a partition function were substantially less for permethylated R,R-trehalose and laminarabiose, compared to their native counterparts at any . On the other hand, strong interresidue hydrogen bonding at ) 1.5 for the global minimum structures of cellobiose and maltose caused those models to be more rigid than their permethylated counterparts. All permethylated models were less flexible than their native counterparts at ) 7.5 and their backbone analogues based on tetrahydropyran calculated at ) 1.5.

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Characterization of tri-o-methylcellulose by one- and two-dimensional NMR methods

Cited by 15 publications

References 39 publications

Brønsted acid-catalyzed polymerization of ε-caprolactone in water: A mild and straightforward route to poly(ε-caprolactone)-graft -water-soluble polysaccharides

Brønsted acid-catalyzed polymerization of ε-caprolactone in water: A mild and straightforward route to poly(ε-caprolactone)-graft -water-soluble polysaccharides

Methylcellulose, a Cellulose Derivative with Original Physical Properties and Extended Applications

Conformational Analyses of Native and Permethylated Disaccharides

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