Abstract
In this work, the possibility of obtaining biohydrogels from carboxymethyl cellulose (CMC) and hydroxyethyl cellulose (HEC) using citric acid (CA) as a cross-linking agent was investigated. CMC and HEC used in the work were synthesized from microcrystalline cellulose obtained from sunflower seed husks (SFH). More specifically, local agricultural waste was used as a raw material source for the monomers used to produce the hydrogel. The chemical and crystal structures of the synthesized hydrogel were analyzed using FTIR and XRD techniques, with comparisons made to the initial monomers.The thermal stability of the synthesized hydrogel was 580°C, and the mechanical strength was 134 kPa. According to the kinetics of swelling in water, it was found that the degree of swelling in the first two hours was 500%. The hydrogel synthesized on the basis of cellulose showed high potential for use as a biodegradable composite sorbent for purification of water from heavy metals, drug delivery and protect plants from drought. Key words: biohydrogel; carboxymethylcellulose; hydroxyethylcellulose; citric acid; swelling kinetics.