Optimization of Ceric Ammonium Nitrate and Ferrous Ammonium Sulfate in the Synthesis of Chitosan-Graft-Maleic Anhydride

Abstract

Amongst various methods for chitosan modification, grafting process is one of the promising techniques to alter chitosan surface properties. Maleic anhydride (MA) was grafted onto chitosan in the presence of an initiator to produce chitosan-graft-maleic anhydride (CTS- graft-MA). In this study, we compared and optimized two types of initiators: Ceric Ammonium Nitrate (CAN) and Ferrous Ammonium Sulfate (FAS) with various ratios in the synthesis of chitosan-graft-maleic anhydride. Chitosan was dissolved in dilute acetic acid solution. Subsequently, the initiator was added into solution to initiate the reaction and maleic anhydride was added immediately afterward. The reaction was carried out for 45 minutes at 70 °C with 430 rpm of agitation. The results of Fourier Transformed Infrared (FTIR) spectroscopy showed an appearance of a new peak at 1705.07 cm⁻¹ which belongs to C=O bands for both initiators. To find out the optimum results from CAN and FAS, the back-titration method was performed. The optimum ratio for CAN is 2.51% with the acidic content 5.4421 mmol/gr, while FAS is 0.268% with the acidic content 4.4673 mmol/gr. In conclusion, CAN is more effective than FAS to initiate the grafting process on CTS-graft- MA.