Effects of the quantity and structure of hydrophobes on the properties of hydrophobically modified alginates in aqueous solutions

Alginate is an important polysaccharide with applications in food industry, cosmetics and pharmacy. In this study, three hydrophobically modified alginates with different amount of various hydrophobic groups have been synthesized. Rheology and turbidity measurements have been carried out on polymer solutions in the concentration regime 0.005-2.0 wt %. The rheological results indicate that the introduction of hydrophobic groups induce the formation of intra- or intermolecular associations in the aqueous solutions depending on the polymer concentration and the hydrophobicity. The concentration dependency of the viscosity exhibit different power-law behaviors depending on the concentration regime and the hydrophobic modification. This has been scrutinized in view of theoretical scaling laws presented in the literature.