Preparation of chemically crosslinked chitosan hydrogels with adipic acid and EDAC carbodiimide: Tailored biomaterials for multifunctional applications

Hydrogels are versatile biomaterials with significant potential in agriculture, food preservation, and biomedical applications. Hydrogels are three-dimensional networks of hydrophilic polymers that can absorb and retain large amounts of water or biological fluids. Among the polymers suitable for hydrogel synthesis, chitosan is particularly notable due to its biocompatibility, biodegradability, and antimicrobial properties. This study investigates chitosan characteristics, focusing on its various properties and how they influence its potential applications in the synthesis of chitosan hydrogels crosslinked with adipic acid using the water-soluble carbodiimide N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride (EDAC) to develop multifunctional films for practical applications. The raw materials were characterized using potentiometric titration, Fourier Transform Infrared Spectroscopy (FTIR) and X-ray Diffraction (XRD). The hydrogels were analyzed for morphology and crystallinity through Scanning Electron Microscopy (SEM), FTIR and XRD, comparing samples with and without the addition of the carbodiimide crosslinker. Quantitative analysis of swelling behavior was also conducted using standard buffer solutions. The results showed that crosslinking with adipic acid enhanced the crystallinity of chitosan, while the inclusion of EDAC reduced crystallinity and the degree of swelling, indicating improved crosslinking between polymer chains. These changes in structural and functional properties demonstrate the adaptability of these hydrogels for specific applications. This study underscores the potential of chitosan-based hydrogels as advanced biomaterials.