Synthesis of Cationic Starch Compound Emulsion by Graft Copolymerization with Tea Polyphenols and AEM5700

Abstract An antibacterial biobased compound emulsion is prepared by modifying cationic oxidized starch grafted styrene‐acrylic emulsion with 3‐(trimethoxysilyl)‐propyldimethyloctadecyl ammonium chloride (AEM5700) and tea polyphenols. The biobased compound emulsion exhibits better stability, chemical properties, and antibacterial properties. The structure and surface morphology of biobased compound emulsion are characterized by Fourier Transform infrared spectroscopy (FTIR) and transmission electron microscopy (TEM). The thermal stability of biobased compound emulsion is improved, which can be concluded from the thermogravimetric analysis (TGA). The surface morphology of film is observed by the atomic force microscope (AFM). The wetting property of emulsion film is tested by contact angle test. When the compound ratio is 1.5, the biobased antibacterial compound emulsion has better stability and antibacterial properties. Compared to a single antibacterial agent, the inhibition zone increases by 4–5.5 mm. In addition, the polymerization mechanism of the biobased antibacterial emulsion is analyzed.