| dc.description.abstract | Modification of breadfruit starch into carboxylate starch has been carried out through an oxidation reaction between breadfruit starch (Artocarpus altilis) and nitric acid. The oxidation reaction was carried out with variations in starch mass with nitric acid of 1:1, 1:3, 1:5 and time variations of 4, 6, and 8 hours. The results of carboxylate starch modification were analyzed using an FT-IR spectrophotometer, oxidation degree test, carboxyl content test, solubility test, viscosity test, SEM analysis, XRD analysis, and TGA analysis. The resulting carboxylate starch was analyzed by FT-IR appearing at a wave number of 1729 cm-1 indicating vibrations of the carboxyl C=O group, vibrations at wave numbers of 2937-2922 cm-1 indicating the presence of a –CH sp3 group. Determination of the degree of oxidation was carried out on all variations and the highest DO value was obtained in carboxylate starch with a mass variation of 1:5 at a reaction time of 6 hours, which was 83,43%. Characterization of carboxylate starch with a mass variation of 1:5 at a reaction time of 6 hours resulted in a carboxyl content value = 0,67%, solubility = 35,29% and viscosity = 0,6946 Cp. The results of SEM analysis showed that the granule surface had been broken down due to the oxidation reaction, XRD analysis showed a decrease in crystallinity from 14.0% to 3.2%, and TGA analysis showed a decrease in degradation temperature between natural starch and carboxylate starch from 310°C to 240°C. | en_US |
