Fractionation of unsubstituted cellulose from solutions in either Ni-tren or (N,N-dimethylacetamide + LiCl)

Loske, Stefan; Lutz, Andreas; Striouk, Sergej; Wolf, Bernhard

doi:10.1002/1521-3935(20001001)201:15<1940::aid-macp1940>3.3.co;2-x

Cited by 2 publications

(2 citation statements)

References 4 publications

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“…Microcrystalline cellulose (MCC, AVICEL PH-101, with a 'typical' M n = 10800, M w /M n = 3.00) [35] with DP of 67 was obtained from Aldrich and dried under vacuum at 100°C for 24 h. Ionic liquid 1-allyl-3-methylimidazolium chloride (AMIMCl, 98%) was purchased from Alfa Aesar, USA. 2-Bromoisobutyryl bromide (BriBBr, 98%), dimethylformamide (DMF, 99.9%) tetrahydrofuran (THF, >99.9%), methanol (MeOH, >99.8%), tetrabutylammonium perchlorate (TBAP, >98%), copper(II) bromide (Cu II Br 2 , 99.9%), n-butanol (>99.7%), sulfuric acid (>95%), trifluoroacetic acid (TFA, >99%), dichloromethane (DCM, >99.5%), acidic ion-exchange resin (Dowex Marathon), and sodium hydroxide (NaOH, >98%), were purchased from Aldrich.…”

Section: Methodsmentioning

confidence: 99%

Cellulose-based graft copolymers prepared by simplified electrochemically mediated ATRP

Chmielarz¹

2017

Express Polym. Lett.

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Abstract. Brush-shaped block copolymer with a dual hydrophilic poly(acrylic acid)-block-poly(oligo(ethylene glycol) acrylate) (PAA-b-POEGA) arms was synthesized for the first time via a simplified electrochemically mediated ATRP (seATRP) under both constant potential electrolysis and constant current electrolysis conditions, utilizing only 30 ppm of catalyst complex. The polymerization conditions were optimized to provide fast reactions while employing low catalyst concentrations and preparation of cellulose-based brush-like copolymers with narrow molecular weight distributions. The results from proton nuclear magnetic resonance ( 1 H NMR) spectral studies support the formation of cellulose-based graft (co)polymers. It is expected that these new polymer brushes may find application as pH-and thermo-sensitive drug delivery systems.

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Section: Methodsmentioning

confidence: 99%

Cellulose-based graft copolymers prepared by simplified electrochemically mediated ATRP

Chmielarz¹

2017

Express Polym. Lett.

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“…With regard to a practical realization of this concept the authors themselves were, however, rather skeptical because of minute differences in the densities of the coexisting phases and problems with the formation of emulsions. It is only recently that this polymer incompatibility could be successfully employed for a joint fractionation of two homopolymers, 17 namely cellulose and PMMA. To our knowledge, no attempts have so far been made to utilize the concept to fractionate copolymers with respect to their chemical composition.…”

Section: Resultsmentioning

confidence: 99%

Basis for the Preparative Fractionation of a Statistical Copolymer (SAN) with Respect to Either Chain Length or Chemical Composition

2003

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The possibilities to fractionate copolymers with respect to their chemical composition on a preparative scale by means of the establishment of liquid/liquid phase equilibria were studied for random copolymers of styrene and acrylonitrile (SAN). Experiments with solutions of SAN in toluene have shown that fractionation does in this quasibinary system, where demixing results from marginal solvent quality, take place with respect to the chain length of the polymer only. On the other hand, if phase separation is induced by a second, chemically different polymer one can find conditions under which fractionation with respect to composition becomes dominant. This opportunity is documented for the quasi-ternary system DMAc/SAN/polystyrene, where the solvent dimethyl acetamide is completely miscible with both polymers. The theoretical reasons for the different fractionation mechanisms are discussed.

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Fractionation of unsubstituted cellulose from solutions in either Ni-tren or (N,N-dimethylacetamide + LiCl)

Cited by 2 publications

References 4 publications

Cellulose-based graft copolymers prepared by simplified electrochemically mediated ATRP

Cellulose-based graft copolymers prepared by simplified electrochemically mediated ATRP

Basis for the Preparative Fractionation of a Statistical Copolymer (SAN) with Respect to Either Chain Length or Chemical Composition

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