Microwave assisted grafting kinetic of alginate/sericin with acrylic acid‑co‑acrylamide encapsulation of NPK fertilizer and assessment of release characteristics

In the present study grafted sericin/sodium alginate based encapsulated sustained release NPK fertilizer has been developed. Grafting of sericin/sodium alginate with acrylic acid-co-acrylamide has been performed by using microwave based grafting technique. The ratio of sodium alginate and sericin has been optimized for optimal release of NPK fertilizer, and it was found 0.7:0.3 ratio gives optimum release of encapsulated NPK fertilizer. The developed beads were characterized by studying bead size, encapsulation efficiency, swelling characteristics and cumulative release characteristics. The beads were found to have size range between 0.83 and 1.46 mm. The swelling kinetics of the beads in neutral, acidic and basic medium was found to obey pseudo second order kinetic model with  value more than 0.98. The synthesized beads was found to obey Korsmeyer–Peppas release kinetic model.