title: Cellulose carboxylate/tosylate mixed esters: Synthesis, properties and shaping into microspheres.
abstract: Cellulose carboxylate/tosylate mixed esters (Cel-Carboxy/Ts) were synthesized with constant degree of tosylation, DSTs=0.98 and variable degree of acylation, DSCarboxy; acetate, butanoate, and hexanoate. The tosylate (Cel-Ts) was prepared by reacting cellulose with tosyl chloride in presence of trimethylamine. The mixed esters were obtained by reacting Cel-Ts with carboxylic acid anhydride. The dependence of the following on DSCarboxy was investigated: IR data, including νCO, νSO and peak area (CO); empirical polarity of the films, determined by an adsorbed perichromic dye. We employed these parameters to determine DSCarboxy. Relative to ester saponification, these spectroscopic methods are convenient, expedient, and require much less sample. Mixed esters prepared physically from cellulose tosylate and tosylate/acetate behave only qualitatively similar to (Cel-Carboxy/Ts). The mixed esters were dissolved in acetone and regenerated in water as homogeneous microspheres.
authors: Institute of Chemistry, The University of São Paulo, P.O.B. 26077, São Paulo, SP 05513-970, Brazil; São Paulo State Institute of Technological Research S.A., Av. Prof. Almeida Prado, 532, São Paulo, SP 05508-901, Brazil.
authors: Daniela C
authors: DC
authors: Ferreira
authors: Institute of Chemistry, The University of São Paulo, P.O.B. 26077, São Paulo, SP 05513-970, Brazil.
authors: Gustavo S
authors: GS
authors: Bastos
authors: Institute of Organic and Macromolecular Chemistry, Center of Excellence for Polysaccharide Research, Friedrich Schiller University of Jena, Humboldtstrasse 10, 07743 Jena, Germany.
authors: Annett
authors: A
authors: Pfeifer
authors: Institute of Organic and Macromolecular Chemistry, Center of Excellence for Polysaccharide Research, Friedrich Schiller University of Jena, Humboldtstrasse 10, 07743 Jena, Germany. Electronic address: thomas.heinze@uni-jena.de.
authors: Thomas
authors: T
authors: Heinze
authors: Institute of Chemistry, The University of São Paulo, P.O.B. 26077, São Paulo, SP 05513-970, Brazil. Electronic address: elseoud@usp.br.
authors: Omar A
authors: OA
authors: El Seoud
mesh_terms: D001557:Benzenesulfonates / Q000737:chemistry*; D002482:Cellulose / Q000737:chemistry*; D004952:Esters / Q000138:chemical synthesis / Q000737:chemistry; D008863:Microspheres
chemical_list: C573194:4-methylbenzenesulfonic acid; D001557:Benzenesulfonates; D004952:Esters; D002482:Cellulose
keywords: Cellulose carboxylate/tosylate; Cellulose mixed esters; Film polarity; IR of; Mixed esters; Nanospheres of