METHOD FOR IMPARTING WATER RESISTANCE TO POLYSACCHARIDE MOLDED ARTICLE

摘要

PROBLEM TO BE SOLVED: To impart water resistance to a polysaccharide molded article which is poor in water resistance due to high hydrophilicity by chemically bonding a prolamine such as zein to the surface of the polysaccharide molded article. SOLUTION: A solution of a prolamine such as zein in an alcohol having 1-4 carbon atoms or acetone is contacted with the surface of a polysaccharide molded article containing a prolamine-bonding functional group, preferably a carboxyl group or an amino group, in the presence of carbodiimide to chemically bond the prolamine and impart water resistance to the polysaccharide. The contact between the surface of the polysaccharide molded article and the prolamine is implemented by immerging the polysaccharide molded article in the prolamine solution or by coating or spraying the prolamine solution to the surface of the polysaccharide molded article. Water resistance is considered to be imparted because the prolamine forms a chemically stable bond with the functional group on the surface of the polysaccharide molded article and the surface of the polysaccharide molded article is coated with water- resistant prolamine molecules.