%0 Journal Article
%T Cellulose Acetate Sulfate as a Lyotropic Liquid Crystalline Polyelectrolyte: Synthesis, Properties, and Application
%A D. D. Grinshpan
%A T. A. Savitskaya
%A N. G. Tsygankova
%A S. E. Makarevich
%A S. M. Tretsiakova
%A T. N. Nevar
%J International Journal of Polymer Science
%D 2010
%I Hindawi Publishing Corporation
%R 10.1155/2010/831658
%X The optimal conditions of cellulose acetate sulfate (CAS) homogeneous synthesis with the yield of 94¨C98£¿wt.% have been determined. CAS was confirmed to have an even distribution of functional groups along the polymer chain. The polymer was characterized by an exceptionally high water solubility (up to 70£¿wt.%). The isothermal diagrams of its solubility in water-alcohol media have been obtained. CAS aqueous solutions stability, electrolytic, thermal, and viscous properties have been defined. The main hydrodynamic characteristics such as intrinsic viscosity, Huggins constant, and crossover concentration have been evaluated. The parameters of polymer chain thermodynamic rigidity have been calculated. The formation of liquid crystalline structures in concentrated CAS solutions has been confirmed. CAS was recommended to be used as a binder for the medicinal forms of activated carbon and carbon sorbent for water treatment, hydrophilic ointment foundation. 1. Introduction Synthesis, properties study, and application of polymer liquid crystals has recently become a promising trend in high molecular compounds chemistry. It has gained a great significance along with an intensive development of low-molecular-weight liquid crystals science. Liquid crystalline (LC) polymers and their solutions have an immediate practical interest in industry of synthetic fibers¡ªfor manufacturing extra strong composite materials, in medicine and pharmacy¡ªfor design of drugs with improved bioactivity, in research studies¡ªfor modeling a series of processes occurring in living organisms. From this point of view, cellulose and its derivatives appear to be quite attractive objects. Cellulose derivatives such as hydroxypropyl cellulose; cellulose diacetate, triacetate, and acetate butyrate and so forth, are shown to experience the development of an LC order in the arrangement of the anisometric macromolecules in the presence of a relevant solvent at a certain critical polymer concentration. However, cellulose electrolytes have not been studied so far. Their macromolecules contain ionogenic groups that lead to an increased rigidity of polymer chain, and provide for their high solubility in aqueous media. Salts of cellulose mixed ester, cellulose acetate sulfate (CAS), can be related to this category of derivatives [1¨C5]. Presence of sulfate groups confers high hydrophilic properties to cellulose derivatives, and, therefore, they become soluble in water at degree of substitution (DS) as low as 0.4¨C0.6 [6]. Cellulose derivatives, having strong polyelectrolyte properties, can be prepared by
%U http://www.hindawi.com/journals/ijps/2010/831658/