Cereal Chem 39:1 - 15. | VIEW
Polymeric Products from the Reaction of Dialdehyde Starches with Chlorine in Methanol. Preparation and Properties.
W. C. Schaefer, C. R. Russell, and C. E. Rist. Copyright 1962 by the American Association of Cereal Chemists, Inc.
Periodate-oxidized corn starches, commonly called dialdehyde starches (DAS), were reacted with chlorine dissolved in methanol to give a new series of colorless polymers containing a variety of combinations of aldehyde, carboxyl, and methoxyl groups. The aldehyde content of the starting materials ranged from a trace (unmodified corn starch) to 1.9 groups per glucose residue. After reaction with methanolic chlorine, the D.S. of functional groups ranged from 0.01 to 0.34 for aldehyde groups, from 0.005 to 0.37 for carboxyl groups, and from 0.05 to 1.53 for methoxyl groups. Intrinsic viscosities indicated that some polymer chain scission occurs during reaction with methanolic chlorine. However, microscopic examination of granules before and after treatment revealed no discernible changes in appearance, except with highly oxidized DAS. A wide range of aqueous paste characteristics of the reaction products was available, depending upon starting aldehyde content, reaction conditions, and pH during pasting. Properties of some products indicate a need for further studies in certain areas of potential application. For example, the product derived from unmodified starch may have value as a thin-boiling starch; the product from 5% DAS, as a coating adhesive; and that from 31% DAS, as a textile size.