Preparation of abamectin-loaded porous acrylic resin and controlled release studies

Abstract

A polyacrylic high oil-adsorption resin was prepared by a suspension polymerization method with butyl acrylate and methyl methacrylate as monomers, benzoyl peroxide as an initiator, poly(vinyl alcohol) (PVA-1788) as a dispersing agent, and divinyl benzene as a cross-linking agent. The effects of dispersing agent, pore-forming agent and cross-linking agent on resins structures were revealed. The maximum specific surface areas and pore volumes of the resulting resins were 853.8 m2/g and 1.188 cm3/g, respectively. These structural parameters endowed excellent adsorbability to the resins. Abamectin, a macrolide insecticide, was selected as a model pesticide, and cyclohexanone was investigated as solvent in adsorption tests. The adsorption isotherms illustrated that adsorption was an endothermic process, and the optimum adsorption temperature was 293 K. Fourier transform infrared spectroscopy, thermogravimetric analysis, and X-ray diffraction results suggested that abamectin-loaded resins were prepared. The sustained release data indicated that the pesticide-loaded resins exhibited a sustained pesticide release pattern, and the releasing process continued over 15 days in an alcohol medium with the final release rate of over 90 %. These studies established a theory and experimental foundation for the actual application of this method. Meanwhile, the pesticide-loaded resins could be applied to actual production process by adding proper adjuvants in their compositions.