Synthesis And Study Of Salt-Tolerant Super Absorbent Resin

In this thesis, The poly(acrylic acid) based superabsorbent resin (SAR) was synthesized via inverse suspension polymerization and using ammonium persulfate (APS) as the initiator and N,N’-methylene-bis-acrylamide (MBA) as the cross-linking agent. The effects of neutralization degree, water oil ratio and monomer concentration on the water absorbing properties were detailed studied in SAR based on acrylic acid and acrylamide copolymers When the contents of initiator and cross-linking agent were0.3wt%and0.04wt%of the AA and AM monomers, and the degree of neutralization was75%, the resin shows the best absorption capacity. The SAR’s absorption capacity with tap water and0.9%NaCl solution reached538g/g and93g/g, respectively. The following methods were used to improve the salt tolerance properties of SAR:1. A quaternary ammonium cationic monomer (Methacrylamido propyl trimethyl ammonium chloride) was added to increase ion concentration inside the polymer network, which also increased the osmotic pressure difference inside the resin and outside in the salt water. The salt tolerance of SAR is improved.2. An anionic monomer (Sodium2-acrylamido-octyl sulfonate) was also used to increase the whole ion concentration of SAR When the content of initiator was0.2wt%, the cross-linking agent was0.02wt%and the content of NaAMC8S was0.5wt%of AA and AM monomer, and the degree of neutralization was75%, the SAR’s absorption capacity with tap water and0.9%NaCl solution reached601g/g and154g/g, respectively.The chemical structure and heat properties of the SAR were characterized by Infrared spectroscopy (IR), Thermogravmetric analysis (TGA),Differential scanning calorimetry (DSC).etc.