Preparation of oxidized corn starch with high degree of oxidation by fenton-like oxidation assisted with ball milling

[Display omitted] •Ball milling was used to assist the preparation of OCS by Fenton-like oxidation.•The prepared OCS demonstrated a high degree of substitution and low apparent viscosity.•This method is environmental friendly. This work aims at preparing oxidized corn starch (OCS) with high degree of oxidation using a green method. It was proposed to prepared OCS by hydrogen peroxide (H2O2) in a Fenton-like oxidation assisted with ball milling. The effects of cupric sulfate concentrations, water content, H2O2 dosage, pH and milling media on carboxyl or carbonyl content of the obtained OCS were investigated. The optimum conditions were established, under which degree of carboxyl and carbonyl substitution of OCS reached up to 0.950 and 0.573, respectively. The oxidation kinetics of starch with H2O2 was studied for a better understanding of the oxidation process. Rapid viscosity analysis (RVA), FTIR and XRD were used to characterize OCS samples. RVA demonstrated an apparent viscosity of 10∼12 mPa·s for the 10 % OCS solution at 95 ℃. FTIR revealed the formation of carbonyl group on starch molecules. XRD demonstrated the granules structure of OCS, however, with a greatly reduced crystallinity. The OCS as green materials has potential applications in textile and food industry.