Water Management within Tragacanth gum-g-polyitaconic Acid Hydrogels

Abstract

In our investigation, we have studied the interaction of the water molecules with the hydrophilic sites in itaconic acid grafted Tragacanth gum copolymer. The water existed in two different states within the hydrogel matrix. There is one fraction of water which has close interaction with functional groups and does not undergo freezing during cooling. Besides, this the other type of water undergoes thermal transitions and freezes at-50°C. The water management within the grafted matrix seems to be strongly governed by hydrophilicity, crosslinked density and functionality. The water uptake by the hydrogel increased significantly as the degree of grafting increased, in spite of the increasing crosslink density of the matrix. Results have been explained in terms of the carboxylic groups and their ionization which has an overriding influencing the hydrogel structure leading to a more amenable structure for the water diffusion.