| 摘要 |
PURPOSE:To obtain the titled cyanoethyl-pullulan suitable as a binder for ELP, by reacting pullulan depolymerized to a specified viscosity with acrylonitrile in the presence of an alkali catalyst. CONSTITUTION:Pullulan depolymerized to a viscosity of below 20cP as measured in a 20wt% aqueous solution at 20 deg.C is reacted with acrylonitrile in the presence of an alkali catalyst. The pullulan used is one which is accumulated outside cells as mucous matter by cultivating strains of the genus Pullularia under aeration and obtained by separating and purifying the cells. The MW of the pullulan in this case may vary with conditions including temperature, pH, amount of air, kind, concentration, etc., of salts used in cultivation, and may be above 30,000. A process for lowering the viscosity by depolymerizing cellulose, cellulose derivatives, starch, or starch derivatives can be applied to depolymerize pullulan. |
