Recently, biomass-based polymers from renewable resources have received increasing focus
owing to the depletion of petroleum resources. Natural polysaccharides such as cellulose,
hemicellulose, and starch are among the candidates from natural resources for biomass
polysaccharide products including bioplastics. Although several kinds of neutral or anionic
polysaccharides such as chitin, alginic acid, hyaluronic acid, heparin, and chondroitin sulfate
exist in nature, natural cationic polysaccharides are quite limited. Chitin is second only to
cellulose as...