Synthesis of Cotton Linter-Based Crosslinked Polymer Hydrogels and Their Application in Agriculture

Biodegradable hydrogels based on cotton linter were synthesized via free-radical crosslinking of partially neutralized acrylic acid. Ammonium persulfate was used as an initiator and N,N′-methylenebisacrylamide as a crosslinker to form a three-dimensional polymer network. The hydrogels exhibited high water absorption capacities in distilled water (450–800 g/g), saline solution (120–250 g/g), and pH-dependent media. Soil burial tests showed gradual biodegradation with 70–85% mass loss after 180 days. Pot experiments demonstrated improved soil moisture retention and increased plant biomass by up to 28% compared to the control. These results indicate that cotton linter-based crosslinked hydrogels are promising, environmentally friendly materials for agricultural water management.