The Impact of Water and Some Salt Solutions on Some Properties of Hydrophilic Acrylamide Copolymeric Hydrogels

Abstract

A series of polyelectrolyte hydrogels ranging from 92-98wt% were synthesized by copolymerization of acrylamide, AAM with 2-acrylamido-2-methyl propane sulphonic acid, AMPS using 0.001g APS as initiator in the presence of 30wt% H₂O and 1.0wt% ethylene glycol dimethacrylate,EDMA as cross-linking agent. The final copolymers was obtained in the form of glassy and transparent roads at room temperature, these roads were soaked in water for two days to remove unreacted monomers. The swelling behavior of the hydrogels was studied in distilled water and salt solutions of 1.5 mol/l each of NaCl and KCl. The Swelling in water shows decreasing values of q, LE, Ø₁, EWC% and increasing polymer volume fraction, Ø₂ by increasing acrylamide, due to increasing hydrophobicity and decreasing the hydrophilicity. The swelling in salt solutions shows a decreasing in the values of ESSNa%, WCNa%, SCNa%, ESSK%, WCK% and SCK% by increasing acrylamid monomer in the feed due to increasing the hydrophobicity and decreasing the ionized ionic groups (SO₃H). The increasing values of ESSNa%, WCNa% and SCNa% compared with the values of ESSK%, WCK% and SCK% respectively, is due to the higher charge density of sodium ion than that of potassium ion.