PREPARATION OF STARCH SUCCINATES BY REACTIVE EXTRUSION

The succinylation of cornstarch by extrusion processing has been studi ed. Several different factors affecting the succinylation of starch we re investigated including water content, succinic anhydride quantity, catalyst type and quantity, and reaction temperature. The degree of su bstitution (DS) increases with decreasing water content and increasing succinic anhydride quantity. Higher temperature favors higher DS usin g sodium bicarbonate as catalyst while the opposite is true using magn esium hydroxide as catalyst. Of the three catalysts used, sodium bicar bonate is best. Aqueous solubility and viscosity of the starch succina tes tend to increase with increasing DS. Based on the results of aqueo us solution viscosity, some samples appear to be promising as commerci al thickening agent.