| 摘要 |
PURPOSE:To obtain a molded hydrous gel which has excellent water resistance, high strength, and rubbery elasticity and is utilizable as, e.g. a carrier for a bioreactor by molding a poly(vinyl alcohol) solution and then acetalizing the polymer. CONSTITUTION:A poly(vinyl alcohol) (PVA) solution is molded, and the PVA is then acetalized. Examples of the molding method include (1) one in which the pH of the PVA solution is regulated to 8 or higher and the resulting solution is contacted with a liquid containing a boric acid compound; (2) one in which a boric acid compound is added to the PVA solution and the solution is contacted with a basic solvent, e.g. sodium hydroxide; (3) one in which a solution of one or more water-soluble high-mol. polysaccharides which are capable of gelling upon contact with a cation is added to the PVA solution and the resulting mixture is contacted with an aqueous solution of a compound containing a cation; and (4) one in which the PVA solution is contacted with a poor solvent for PVA, e.g. methanol. |
