ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

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

Witta Kartika Restu, Rista Siti Mawarni, Evi Triwulandari, Muhammad Ghozali, Tazkia Qonita Zahra, Nova Rachmadona, Purwantiningsih Sugita, and Harry Agusnar

Research Center for Chemistry, National Research and Innovation Agency (BRIN), South Tangerang, Indonesia

E-mail: witt001@brin.go.id

Received: 12 September 2023  Accepted: 15 December 2023

Abstract:

The present study synthesized baked hydrogels by crosslinking reactions from the sugar palm starch and modified chitosan using citric acid as a crosslinker 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. The morphology was observed with scanning electron microscopy, showing the porosity in the structure. The thermal properties were marked using differential scanning calorimetry 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%. The adsorption capacity of the baked hydrogel, despite its simple preparation method, is relatively high. This is evidenced by its effective ability to adsorb contaminants, which can be attributed to its crosslinking formation. Based on the observed features and experimental outcomes at the laboratory scale, it can be affirmed that the utilization of sugar palm starch and modified chitosan in baked hydrogel exhibits potential for environmental applications pertaining to contamination removal.

Graphical abstract

Keywords: Baked hydrogel; Sugar palm starch; Modified chitosan; Citric acid; Methylene blue

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-023-03286-1

Chemical Papers 78 (5) 2977–2986 (2024)