ДИФФЕРЕНЦИАЛДЫ ТЕРМОГРАВИМЕТРИЯЛЫҚ ӘДІСПЕН КАОЛИН, АКРИЛАМИД ЖӘНЕ КРАХМАЛ НЕГІЗІНДЕ АЛЫНҒАН ГИДРОГЕЛЬДЕРДІҢ ҚАСИЕТІН ТАЛДАУ

Abstract

This study investigates the physicochemical and thermal properties of superabsorbent hydrogel composites synthesized from starch, acrylamide, and kaolin using free-radical copolymerization and chemical cross-linking. Natural starch was employed as a biodegradable polymer matrix, while acrylamide was used to enhance hydrophilicity and swelling capacity. Kaolin, a layered aluminosilicate mineral, was introduced as an inorganic filler to improve structural integrity and thermal stability of the hydrogel system. The synthesized hydrogels were characterized using Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and differential thermogravimetric analysis (TG/DTG/DSC). FTIR results confirmed the successful copolymerization and chemical interaction between starch, acrylamide, and kaolin, leading to the formation of a three-dimensional cross-linked network. SEM analysis revealed a porous morphology favorable for water absorption. Thermogravimetric analysis demonstrated multistage thermal degradation behavior and confirmed that the presence of kaolin significantly enhanced the thermal stability of the composite hydrogels. The results indicate that kaolin acts as an additional cross-linking center, strengthening the polymer matrix and regulating swelling behavior. Owing to their high water absorption capacity, structural stability, and eco-friendly composition, the synthesized hydrogels show strong potential for agricultural and environmental applications, particularly as soil moisture retainers and sustainable functional materials.