Properties of regioselectively substituted anionic cellulose polyelectrolytes

Abstract

In relation to recent results of regioselective reactions in cellulose chemistry, the synthesis and properties of important cellulose polyelectrolytes, namely of carboxymethyl cellulose and cellulose sulfate are described. Synthesis paths leading to such cellulose polyelectrolytes with an unusual pattern of the distribution of functional groups were developed using protecting group technique, activation effects, as well as phase separation phenomena. The regioselective distribution of functional groups within the anhydroglucose repeating unit at fixed degree of substitution and along the polymer chain is shown to be especially relevant, e.g., to solubility, salt tolerance, and interaction with human blood.

Detailed investigation on the molecular structure of carboxymethyl cellulose with unusual substitution pattern by means of an enzyme-supported analysis

“…A considerable amount of work was done to derivatise polyglucans in a regioselective manner and to elucidate the influence of the substitution patterns within the repeating unit on the chemical, physical and biological properties of the polysaccharides. [3] Thus, it was shown that the pattern of functionalisation on this level determines the heparinoide effect of differently substituted cellulose sulfates [4] . The thermoreversible gel-formation of methyl cellulose can be adjusted as well by the functionalisation pattern, which is contributed to the hydrogen bond system of the remaining OH units.…”

Influence of Charge Density and Distribution on the Internal Structure of Electrostatically Self-assembled Polyelectrolyte Films

“…The DS of the cellulose sulfate samples ranges from 0.33 to 1 average charges/repeat unit. The distribution of the sulfate groups over the repeat unit varies widely and is related to detailed chemistry employed to synthesize the samples. , For instance, 2b,c show a statistical distribution, reflecting that the order of reactivity for the different positions in a glucopyranose unit is typically C6 > C2 > C3. For carboxymethyl cellulose, prepared under standard conditions, this order is somewhat different.…”

“…For carboxymethyl cellulose, prepared under standard conditions, this order is somewhat different. For carboxymethylation of cellulose in ethanol or 2-propanol and activation with an aqueous NaOH solution, the order is typically C2 ≥ C6 > C3 . Selective reactions on precursor polymers (generally, cellulose acetates) provided the nonstatistical cellulose sulfate derivatives.…”

“…Materials. The synthesis of the cellulose sulfate samples was described elsewhere; an overview of the properties and degree and pattern of substitution is given in Table . The 2,3-bis(carboxymethyl) cellulose sample ( 3b ) was a gift from Prof. Heinze (University of Jena, Jena, Germany); its synthesis was described elsewhere .…”

Influence of ionic liquid-like cationic pendants composition in cellulose based polyelectrolytes on membrane-based CO2 separation

“…(Chen et al, 2014;Deng et al, 2016;Lam et al, 2016;Li, Wang, Nagai, Nakagawa, & Mau, 1998;Nikolaeva et al, 2018). While several articles report on properties and perfor mance of CA-based polyelectrolytes, the effect of PE composition on their performance in membrane-based CO 2 separation remains virtually unexplored (Gericke, Liebert, & Heinze, 2009;Klemm, Heinze, & Wagenknecht, 1996;Mazoniene, Joceviciute, Kazlauske, Niemeyer, & Liesiene, 2011).…”