Fibrous long‐chain organic acid cellulose esters and their characterization by diffuse reflectance FTIR spectroscopy, solid‐state CP/MAS 13C‐NMR, and X‐ray diffraction

Jandura, Peter; Kokta, B. V.; Riedl, Bernard

doi:10.1002/1097-4628(20001114)78:7<1354::aid-app60>3.3.co;2-m

Cited by 33 publications

(44 citation statements)

References 6 publications

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“…5, the microcrystalline cellulose displays the typical XRD pattern of cellulose I, with the main diffraction peaks at around 2h 14.95°, 16.54°, 22.66°, and 34.60°, normally corresponding to the diffraction planes 101, 10ī, 002, and 040, respectively. In the XRD spectra of cellulose derivatives, the characteristic peaks of 101, 002, and 040 planes have been weakened or disappeared, while a new broad diffraction peak between 2h = 18°and 21°is obviously observed, which is normally attributed to the amorphous regions of cellulose chains [42]. Similar results had been reported by Freire et al [26].…”

Section: X-ray Diffractionsupporting

confidence: 85%

Synthesis and characterization of hydrophobic long-chain fatty acylated cellulose and its self-assembled nanoparticles

Guo

Wang

et al. 2012

Polym. Bull.

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In this paper, a series of cellulose-based hydrophobic associating polymers were prepared by homogeneous acylation of microcrystalline cellulose with long-chain acyl chlorides including octanoyl, lauroyl, and palmitoly chlorides in the solvent of N,N-dimethylacetamide/lithium chloride (DMAc/LiCl) using pyridine as acid scavenger. Through controlling the chain length of fatty acyl chlorides and the molar ratio of acyl chlorides vs anhydroglucose unit, the hydrophobic cellulose derivatives with degrees of substitution in the range of 0.02-1.75 were successfully obtained. The chemical structures and properties of these hydrophobic derivatives were characterized by elemental analysis, FT-IR, CP/MAS 13 C NMR, X-ray diffraction, and the thermogravimetry analysis. It was also found that, the cellulose-based polymers achieved an excellent solubility in organic solvents, such as benzene, methylbenzene, and pyridine, with the introduction of hydrophobic side chain into the cellulose backbone. Furthermore, it was found that these hydrophobic cellulose derivatives could self-assemble into spherical nanoparticles in aqueous solution, which indicates a tremendous potential of applications in pharmaceutical and medical fields.

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Section: X-ray Diffractionsupporting

confidence: 85%

Synthesis and characterization of hydrophobic long-chain fatty acylated cellulose and its self-assembled nanoparticles

Guo

Wang

et al. 2012

Polym. Bull.

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“…The samples, as expected, gave an amorphous pattern with broad peaks. These broad peaks may have originated from smaller size starch crystals as the acetylation reaction continued (Jandura et al 2000).…”

Section: X-ray Diffractionmentioning

confidence: 99%

Synthesis and Characterization of Starch Acetates with High Substitution

Miladinov²,

2004

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Cereal Chem. 81(6):735-740Acetylation of high-amylose (70%) maize starch to high degree of substitution (DS) was studied by reacting starch with acetic anhydride using 50% aqueous NaOH as the catalyst. DS increased with increasing reaction times and increasing ratios of acetic anhydride to starch. Reaction efficiency (RE) increased with longer reaction times and decreased with increases in the ratios of acetic anhydride to starch for extended reaction times. Increasing the amount of NaOH increased both DS and RE. A series of starch acetates with DS values of 0.57-2.23 were prepared and their crystalline structures, chemical structures, thermal stability, and morphological properties were investigated. After acetylation, and as DS increased from 0.57 to 2.23, the crystalline structures of starch steadily disappeared. The carbonyl group's peak at 1,740 cm -1 appeared in the FTIR spectra. The intensity of this peak increased with a decrease in the peak intensity of the hydroxyl groups at 3,000-3,600 cm -1 , indicating that the hydroxyl groups on starch were replaced by the acetyl groups. Thermal stability of starch acetates increased. The smooth surface of the starch granules became rough with acetylation. Further acetylation led to the loss of the starch granules and the formation of beehive-and fibrouslike structures.

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“…Several articles have been published considering the surface modification of cellulose, especially of cellulose fibers (Belgacem and Gandini 2005;Freire et al 2006a, b;Jandura et al 2000a, b;Pasquini et al 2006). These studies have mostly involved modification of macroscopic cellulose, but during recent years, more and more articles have been published in which cellulose nanoparticles have also been modified.…”

Section: Introductionmentioning

confidence: 99%

“…They crosslinked whiskers with poly(methyl vinyl ether-co-maleic acid) and poly(ethylene glycol). A well-known and attractive way to prepare ''greener'' fillers for polymeric composites is the esterification of cellulose with fatty acids (Battista et al 1978;Bondeson et al 2006;Freire et al 2006bFreire et al , 2008Grun and Wittka 1921;Jandura et al 2000a, b;Malm et al 1951Malm et al , 2000Pasquini et al 2006;Shimzu and Hayashi 1989). This is because of the renewability and biodegradability of nature-based fatty acids.…”

Section: Introductionmentioning

confidence: 99%

Heterogeneous modification of various celluloses with fatty acids

et al. 2010

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Heterogeneous modification of various types of cellulose (microcrystalline cellulose, cellulose whiskers and regenerated cellulose) was performed with long-chain fatty acids by an esterification reaction. The differences in reactivity between the celluloses were studied as well as the influences of the chain length and double bond content of the fatty acids. The success of the modification reaction and the structure of modified samples were studied with diverse characterization methods. Surface modification changed the thermal stability of cellulose by decreasing the degradation temperature but also made the pyrolysis curve two-stepped due to the double bonds in the fatty acid chain. It was observed that the nature of the fatty acid affected the degree of substitution (DS). The longer the fatty acid chain was, the lower was the DS. Fatty acids with increased double bond content gave decreased DS. Regenerated cellulose seemed to have the highest surface reactivity due to the distinct morphological structure, which also led to a much lower quantity of fatty acids attached to the structure than for other modified cellulose particles. The mixture of tall oil fatty acids behaved in the same manner as the commercial fatty acids, proving to be an excellent ''green'' choice for this kind of application.

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Fibrous long‐chain organic acid cellulose esters and their characterization by diffuse reflectance FTIR spectroscopy, solid‐state CP/MAS 13C‐NMR, and X‐ray diffraction

Cited by 33 publications

References 6 publications

Synthesis and characterization of hydrophobic long-chain fatty acylated cellulose and its self-assembled nanoparticles

Synthesis and characterization of hydrophobic long-chain fatty acylated cellulose and its self-assembled nanoparticles

Synthesis and Characterization of Starch Acetates with High Substitution

Heterogeneous modification of various celluloses with fatty acids

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