| abstract |
Polysaccharide esters containing aldehyde and acetal groups having the structural formulas <IMAGE> +TR <IMAGE> are prepared by reacting a polysaccharide, such as a starch, gum, or cellulose, with an acetal-containing reagent which contains a functional group reactive with the hydroxyl groups of the polysaccharide; Z is a multivalent organic group: A and A' are independently a lower alkyl or together form at least a 5-membered cyclic acetal; x is at least 1; and y is at least 1. When x is >1 the esters are crosslinked. Typical reagents for introducing the acetal group include 3,3-diethoxypropionyl guanidine (itself a novel compound) and 4-(methylaminoacetaldehyde dimethyl acetal)-4-oxo-butanoic acid). The derivatives are useful in conventional applications such as coatings, adhesives, paper additives and foodstuffs. |