Rheological Properties and Swelling Kinetics of Hydrogels Based on Polymer Complexes of Pectin and Arabinogalactan

The interaction of pectin and arabinogalactan macromolecules in aqueous solutions has been studied. It is shown that polymer complexes are formed due to hydrogen bonding between macromolecules. Crosslinking of the polymer complex by Са²⁺ ions leads to the formation of hydrogels whose properties are considerably determined by the content of arabinogalactan. At low concentrations of Са²⁺ ions (from 0.05 to 0.15 wt %), the introduction of arabinogalactan contributes to an increase in shear modulus and crosslink concentration and results in a reduction in polymer network sizes compared with hydrogels based on native pectin. With increasing arabinogalactan content the contribution of Fick’s diffusion to swelling of the synthesized hydrogels grows.