These results point to postulate there are interactions between the amino group of acrylamide and the OH present in the anhydroglucose units of starch.
Hydrogen bond interaction between the OH of the anhydroglucose units and the C=O and NH2 groups in the acrylamide grafted in the PP.
DS represents the number of the carboxymethyl groups in the molecular unit of the anhydroglucose units
. In principal, all hydroxyl groups (HO-2, HO-3, and HO-6) in the anhydroglucose unit
can be substituted, and the maximum degree of substitution (DS) is being 3 (Salmi, et al., 1994).
Since the degree of substitution corresponds to the number of cationic groups linked per anhydroglucose unit
(one anhydroglucose unit
bears three OH groups), the theoretical degree of substitution is:
Graft frequency, as measured by the number of anhydroglucose units
per graft, was essentially constant over the starch: acrylamide ratio and temperature range studied.
In the second fast reaction, MAN reacts under alkaline circumstances with the hydroxyl group of the anhydroglucose units
The formation of certain carbonyl groups in the anhydroglucose units
has been shown to account for the yellowing of celluloses [28, 41].
Cellulose is a linear polymer composed of anhydroglucose units
joined by 1-4-[beta]-3-glycosidic bonds.
The degree of substitution (DS) indicates the average number of sites per anhydroglucose unit
on which there are substituent groups.