Polymer Hydrogels: A Review

This review encompasses definitions, classification, main properties, and application of polymer hydrogels. Raw materials and preparation techniques of polymer hydrogels were described. The factors that affect absorption capacity and swelling properties of polymer hydrogels were reviewed. PHG materials are defined as a viscoelastic network structure, swellable and not soluble in water with high absorbent capacity, which may reach 1000 g/g of their dried weight to be termed "superabsorbent polymer hydrogels". PHGs have the ability to release absorbed fluids under certain circumstances.