Formation of supermolecular structures of polysaccharide‐surfactant complexes in aqueous solutions. Influence of the polymer backbone

Abstract

AbstractNovel water‐soluble derivatives of cellulose, amylose and dextran are synthesized and investigated with regard to their special interactions with the anionic surfactant sodium dodecylsulfate (SDS) by means of rheological flow‐ and oscillatory measurements as well as electrolytic conductivity in aqueous solution. The derivatives of amylose and dextran show a continuous adsorption of SDS with increasing surfactant concentration leading to an increase of the viscosity and of the viscous part of the shear modulus of the solution. Only low elastic parts are detectable. In contrast, the behaviour of cellulose derivatives differs extremely with increasing amount of SDS. The viscosity and the elastic part of the shear modulus of aqueous solutions reach a well pronounced maximum and then drop almost to the initial values. A similar behaviour is also observed by adding the cationic surfactant hexadecyltrimethylammonium bromide. It is concluded that the observed differences in properties of the cellulose derivatives on the one side and derivatives of amylose and dextran on the other are cause by the structure of the polymer main chain, because the side groups for all of these polymers are comparable.