Free-standing polysaccharide composite films: Improved preparation and physical properties

Free-standing films of natural polysaccharides were prepared using hot press techniques. Polyion complexes (PICs) made of acidic polysaccharides such as chondroitin sulfate C and chitosan were formed into thin films by hot pressing. The times needed to conduct the process from PIC formation using polysaccharide solutions of two kinds to obtaining films were 30 min or less under appropriate conditions. The resulting films swelled in distilled water to some degree but were not dissolved despite being made of water-soluble polysaccharides. Contact angle measurements supported dense surface structure of the films because of the effects of hot pressing. The films had sufficient mechanical properties to be used as structural materials. Polysaccharide species and film preparation processes affected some film properties. (C) 2015 Elsevier B.V. All rights reserved.