Preparation and Antibacterial Properties of Starch Modified Copper Composites

Corn starch was modified by different methods (acetylation, esterification and amination). The effects of different modification methods on the structure and physicochemical properties of starch were investigated. Four kinds of starches were reacted with copper respectively, and the influence of four kinds of starches on the preparation of copper was investigated under the condition of different addition amounts. Including the morphology and antibacterial effect of copper, it provides a reference for the selection of starch/copper in the future research. In this paper, the structure, morphology and thermodynamic properties of four kinds of starch and modified starch/copper were characterized and analyzed, and the antibacterial properties of starch/copper were tested by enzyme labeling. The results show that: After starch was modified in different ways, its internal crystal structure changed, but the change was small. After modification, the hydrophobicity of starch was improved, and the contact Angle was about 40°. The thermodynamic properties are also improved, and the esterification effect is better. In terms of morphology, the surface of the original starch particles is smooth and most of them are irregular, while the modified starch morphology changes obviously and the particle structure is destroyed. Under the condition of adding the original starch, the copper morphology is mostly irregular, but after adding the modified starch, the copper with hexahedral morphology can be obtained. In addition, the antibacterial effect of starch/copper was not significantly related to the different dosage, and the modification of starch had a certain effect on the antibacterial effect, in contrast, amylamine/copper had the best effect.