Abstract

• In the present study, controlled release formulations have been developed by encapsulating the fungicide, copper oxychloride, for reducing the environmental impact of fungicides within the macromolecular network of alginate and carboxymethyl cellulose based microspheres. Alginate carboxymethyl cellulose beads were prepared in three formulae with various concentrations of carboxymethyl cellulose (SACMC I for 0.25 %, SACMC II for 0.5 %, and SACMC III for 1 % w/v) as a copolymer of sodium alginate and calcium chloride as a cross- linker. The chemical structure, morphology, and thermal properties of the prepared hydrogel beads were characterized by Fourier Transform Infrared Spectroscopy (FT IR), Scanning Electron Microscope (SEM) and Simultaneous Thermogravimetric and Differential Thermal Analysis (TG-DTA), respectively. The swelling ratios of the prepared hydrogel beads were studied by the ASTM method, and the maximum swelling ratio of the SACMC I sample was found to be 80 %. In most of the formulations, the release efficiency of copper oxychloride from the SACMC II sample was 13 % within 7 days. The results were fitted with the Korsmeyer-Peppas kinetics model and the diffusion exponent ‘n’ for all samples were found to be less than 0.89, which shows that the release of fungicides from the samples was diffusion mechanism.