Baked hydrogel from palm starch and modified chitosan for water contaminant removal

Abstract

Abstract The present study synthesized baked hydrogels by crosslinking reactions from the sugar palm starch and modified chitosan using citric acid as a cross-linker and potassium persulfate as the free radical initiator. Sugar palm starch was derived from the sugar palm (Arenga pinnata) plant, extracted from the stem when it no longer produces sugar and fruits. Baked hydrogels were characterized by their physical and chemical properties, including moisture content, water solubility, swelling capacity, and contact angle. From the variation of the obtained baked hydrogels, the moisture contents varied around 11-15%, water solubility was in the range of 28-38% and the degree of swelling was about 153-283%. In terms of contact angle measurement, the highest value was around 65°. The structure formation of chemical linkages among raw materials of the baked hydrogels was studied using Fourier transform infrared spectroscopy (FTIR). The morphology was observed with scanning electron microscopy (SEM), showing the porosity in the structure. The thermal properties were marked using differential scanning calorimetry (DSC) with a range of glass transition temperature of 47-60°C and melting temperature from 190 to 203°C. In their application as the removal of methylene blue as the targeted water contaminant, the baked hydrogels of HSC 3 can absorb methylene blue solution with the highest degradation percentage, reaching 63.10%. This confirmed that sugar palm starch and modified chitosan in baked hydrogel can be applied in the environment for contaminant removal.