Swelling behavior of chitosan/tragacanth gum composite films crosslinked with glutaraldehyde

Natural polymers are absorbing a lot of attention in recent years, mainly due to their biocompatibility and biodegradability. However, from the mechanical point of view, they are not comparable with common synthetic polymers, especially when in touch with water. Among various kinds of natural polymers, chitosan (CS), which is a polysaccharide with animal origin, has been the focus of so many studies. In this study, a mixture of chitosan with tragacanth gum (GT) has been prepared. Tragacanth gum has herbal source and is a natural polymer special to Iran. Composite films of these two polymers were obtained using solution-cast method with the aid of a basic intermediate. The prepared composite films were then chemically crosslinked with the aid of a dialdehyde agent, glutaraldehyde (Glt), in the presence of a Lewis acid catalyst. In this way, we could diminish water sensitivity of the films. The effect of crosslinking agent concentration on swelling behavior of the films in different media has been fully studied. The results revealed that the composite films were crosslinked efficiently