Preparation of Starch/PS-g-MAH Blends and Effect on Controlled Release of Herbicide

Abstract

PS was chemically modified by grafting with maleic anhydride to obtain PS-g-MAH on a single-screw extrude. The blending of starch and PS-g-MAH was carried out to prepare the degradable composite materials by melt extrusion on the extruder. The fractured surfaces of the blends were observed and discussed with the different incorporation of starch by a scanning electron microscope (SEM). The results exhibited that MAH improved the component compatibility of the blends. Then the starch/PS-g-MAH blends were used as the carrier for preparing bensulfuron-methyl CRFs. The bensulfuron-methyl CRFs’ release performance was investigated in the different pH value media by UV analysis. It was shown that the starch/PS-g-MAH matrix has obvious controlled-release function, and the release rate in a basic medium is much higher than in an acidic or neutral medium. The bensulfuron-methyl CRFs should have the longer validity in acidic soil, and have an important potential in reducing inefficient use and impact of pesticides in the environment.