An efficient, one-pot acylation of cellulose under homogeneous reaction conditions

Seoud, Omar A. El; Marson, Guilherme Andrade; Ciacco, Gabriela T.; Frollini, Elisabete

doi:10.1002/(sici)1521-3935(20000501)201:8<882::aid-macp882>3.3.co;2-9

Cited by 36 publications

(63 citation statements)

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“…With regard to the former, we dwell on the degree of polymerization, DP, index of crystallinity, Ic, and the morphological properties of cellulose (Buschlediller and Zeronian 1992;El Seoud el al. 2000a).…”

Section: Introductionmentioning

confidence: 99%

“…For example, it has been shown that the dissolution of several celluloses in NaOH solution depends on their DPs, Ics, and the corresponding supra-molecular structure. Whereas Ic plays a minor role in the dissolution of non-fibrous, low DP microcrystalline cellulose (Isogai and Atalla 1998), it is an important structural feature, along with DP for: The solubility of the biopolymer in non-derivatizing solvent systems, e.g., LiCl/N,N-dimethylacetamide; the conditions of functionalization of solubilized polymer; the yields of the products synthesized (e.g., carboxylic esters) (Buschlediller and Zeronian 1992;El Seoud et al 2000b;El Seoud and Heinze 2005;Schulte et al 2002;Suzuki et al 1992). Effects of the structural characteristics of celluloses on their swelling by organic solvents have been examined in less detail.…”

Section: Introductionmentioning

confidence: 99%

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Cellulose swelling by protic solvents: which properties of the biopolymer and the solvent matter?

Seoud

Fidale

Ruiz³

et al. 2007

Cellulose

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The question posed in the title has been addressed by studying the swelling of celluloses at 20°C by twenty protic solvents, including water; linear-and branched-chain aliphatic alcohols; unsaturated aliphatic alcohols, and alkoxyalcohols. The biopolymers investigated included microcrystalline cellulose, MC, native and never-dried mercerized cotton cellulose, cotton and M-cotton, and native and never-dried mercerized eucalyptus cellulose, eucalyptus and M-eucalyptus, respectively. In most cases, better correlations with the physico-chemical properties of the solvents were obtained when the swelling was expressed as number of moles of solvent/ anhydroglucose unit, nSw, rather than as % increase in sample weight. The descriptors employed in these correlations included, where available, Hildebrand's solubility parameters, Gutmann's acceptor and donor numbers, solvent molar volume, V S , as well as solvatochromic parameters. The latter, employed for the first time for correlating the swelling of biopolymers, included empirical solvent polarity, E T (30), solvent ''acidity'', a S , ''basicity'', b S , and dipolarity/ polarizability, p S * , respectively. Small regression coefficients and large sums of the squares of the residues were obtained when values of nSw were correlated with two solvent parameters. Much better correlations were obtained with three solvent parameters. The most statistically significant descriptor in the correlation equation depends on the cellulose, being p S * for MC, cotton, and eucalyptus, and V S for M-cotton and M-eucalyptus. The best correlations were obtained with the same set of four parameters for all celluloses, namely, solvent pKa (or a S ) b S , p S * , and V S , respectively. These results indicate that the supra-molecular structure of the biopolymer, in particular the average sizes of crystallites and micro-pores, and the presence of its chains in parallel (cellulose I) or anti-parallel (cellulose II) arrangements control its swelling. At least for the present biopolymer/solvent systems, use of solvatochromic parameters is a superior alternative to Hildebrand's solubility parameters and/or Gutmann's acceptor and donor numbers. The relevance of these results to the accessibility of the hydroxyl groups of cellulose, hence to its reactivity, is briefly discussed.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Cellulose swelling by protic solvents: which properties of the biopolymer and the solvent matter?

Seoud

Fidale

Ruiz³

et al. 2007

Cellulose

Self Cite

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“…The cutton pulp was mixed with LiCl/anhydrous DMAc (Aldrich) in proportion to cotton cellulose pulp/LiCl/DMAc (2/8/90). The cellulose was dissolved in the solvent system by heating at 155 °C with mechanical stirring followed by the solvent exchange technique [23]. The cellulose solution was centrifuged at 11000 rpm to eliminate undissolved cellulose fibers.…”

Section: Methodsmentioning

confidence: 99%

Paper Actuators Made with Cellulose and Hybrid Materials

Kim

Yun

Mahadeva

et al. 2010

Sensors

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Recently, cellulose has been re-discovered as a smart material that can be used as sensor and actuator materials, which is termed electro-active paper (EAPap). This paper reports recent advances in paper actuators made with cellulose and hybrid materials such as multi-walled carbon nanotubes, conducting polymers and ionic liquids. Two distinct actuator principles in EAPap actuators are demonstrated: piezoelectric effect and ion migration effect in cellulose. Piezoelectricity of cellulose EAPap is quite comparable with other piezoelectric polymers. But, it is biodegradable, biocompatible, mechanically strong and thermally stable. To enhance ion migration effect in the cellulose, polypyrrole conducting polymer and ionic liquids were nanocoated on the cellulose film. This hybrid cellulose EAPap nanocomposite exhibits durable bending actuation in an ambient humidity and temperature condition. Fabrication, characteristics and performance of the cellulose EAPap and its hybrid EAPap materials are illustrated. Also, its possibility for remotely microwave-driven paper actuator is demonstrated.

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“…In recent years, the cellulose/DMAc/LiCl system has been studied intensively to develop efficient methods appropriate even for industrial application [163,164]. The dissolution procedure and acetylation conditions in DMAc/LiCl allow excellent control of the DS in the range from 1 to 3.…”

Section: Multicomponent Solventsmentioning

confidence: 99%

“…Acetylation of different cellulose types in DMAc/LiCl with acetic anhydride (18 h at 60°C, adapted from[163] and[164])…”

mentioning

confidence: 99%

Esterification of Polysaccharides

Heinze¹,

Liebert²,

Koschella³

2006

Springer Laboratory

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An efficient, one-pot acylation of cellulose under homogeneous reaction conditions

Cited by 36 publications

References 0 publications

Cellulose swelling by protic solvents: which properties of the biopolymer and the solvent matter?

Cellulose swelling by protic solvents: which properties of the biopolymer and the solvent matter?

Paper Actuators Made with Cellulose and Hybrid Materials

Esterification of Polysaccharides

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