title: Water-soluble co-polyelectrolytes by selective modification of cellulose esters.
abstract: Cellulose-based materials are well-suited for biomedical uses, because of their abundance, renewable nature, biodegradability, and relatively low cost. However, the set of commercially available cellulose esters and ethers is limited in number and diversity, and contains no cationically charged cellulose esters. Herein we report a simple, efficient strategy for synthesizing cationic, water-soluble co-polyelectrolytes from commercial, hydrophobic, renewable-based cellulose esters. Cellulose acetate (degree of substitution (DS) 1.78, CA320S), was the exemplary starting material for preparing these cationic polyelectrolytes by a reaction sequence of phosphine-catalyzed bromination and subsequent displacement by an aromatic amine, affording high reaction conversions. We show that these modification techniques can be carried out with essentially complete regio- and chemoselectivity, proceeding in the presence of multiple ester groups, yet preserving those groups. Availability of these novel polysaccharide-based electrolytes starting from uncharged, commercial, inexpensive cellulose esters may open up multiple new application areas, including in several aspects of gene or drug delivery.
authors.affiliation: Department of Chemistry, Virginia Tech, Blacksburg, VA 24061, USA; Macromolecules Innovation Institute, Virginia Tech, Blacksburg, VA 24061, USA.
authors.forename: Shu
authors.initials: S
authors.lastname: Liu
authors.affiliation: Department of Sustainable Biomaterials, Virginia Tech, Blacksburg, VA 24061, USA; Macromolecules Innovation Institute, Virginia Tech, Blacksburg, VA 24061, USA. Electronic address: kjedgar@vt.edu.
authors.forename: Kevin J
authors.initials: KJ
authors.lastname: Edgar
mesh_terms: D001386:Azides / Q000138:chemical synthesis; D002482:Cellulose / Q000031:analogs & derivatives* / Q000138:chemical synthesis* / Q000737:chemistry; D004952:Esters / Q000138:chemical synthesis* / Q000737:chemistry; D054879:Halogenation; D006842:Hydrocarbons, Brominated / Q000737:chemistry; D007093:Imidazoles / Q000138:chemical synthesis; D000071228:Polyelectrolytes / Q000138:chemical synthesis* / Q000737:chemistry; D011726:Pyridinium Compounds / Q000138:chemical synthesis; D012995:Solubility; D014867:Water / Q000737:chemistry
chemical_list: D001386:Azides; D004952:Esters; D006842:Hydrocarbons, Brominated; D007093:Imidazoles; D000071228:Polyelectrolytes; D011726:Pyridinium Compounds; D014867:Water; C005062:acetylcellulose; D002482:Cellulose
keywords: Cationic; Cellulose ester; Polyelectrolyte complex; Regioselectivity; Water-soluble; Zwitterionic