Preparation and Characterization of PP-PVA Blends and Controlled Release System Comprising Bensulfuron-Methyl

Abstract

The matrixes for the controlled release system have been prepared by blending polyvinyl alcohol (PVA) and the reworked granules of recycled polypropylene (PP) with EVA as a compatibilizer on a single screw extruder. The changes of microphase (crystalline) structure and macrophase structure of the PP/PVA blends were investigated by the differential scanning calorimetry (DSC) and scanning electron microscope (SEM). The controlled release formulation (CRF) of Bensulfuron-methyl based on the blends was prepared by means of melt-extrusion, and the release behaviors of bioactive agents were investigated in the different pH buffers with UV spectrophotometer. To a certain extent, the PP/PVA blends showed the components compatibility. The results also showed that there was gradual decrease in the crystallinity of PP with increasing PVA content. The bensulfuron-methyl CRFs exhibited the obviously controlled-release function. The release rate of bensulfuron-methyl was found to be faster in the neutral media than in acidic or basic media. The pesticide CRFs could have an important potential in reducing inefficient use and impact of pesticides in the environment. Moreover, a novel method was provided for recycling and utilizing PP wasters.