Preparation And Properties Of The Composite Absorbent Resin

The super absorbent resin is highly need to improve the land in our country because of the shortage of water resources,serious soil erosion, and the expanding of land desertification. At the same time, the super absorbent resin was required not only to have good water absorption and water retention capacity,but also need to be able to adapt to the changes of temperature and the land salinization,because of the vast territory, the different climate and environment, a lot of land salinization in our country.Acrylic acid(AA), polyvinyl alcohol(PVA) as raw materials, potassium persul-phate as initiator, N, N-methylene bis acrylamide as cross-linking agent, a kind of interpenetrating networks super absorbent(PAA/PVA) was prepared by solution polymerization.The factors that affluent the water absorbency of the resin were investigated, including the amount of initiator, cross-linking agent, AA and PVA mole ratio, reaction temperature and neutralization degree. Using the fuzzy mathematics theory to manipulation the data which is from the orthogonal test, the best reaction conditions were obtained:the mole ratio of AA and PVA was4:1, the dosage of initiator was0.35%, the amount of cross-linking agent was0.1%, the neutralization degree was60%, and the reaction temperature was70C. Under the optimum conditions, the rate of absorbent in water and salt-water of the product was1168g/g and64g/g,the performance of keeping water was72%,the comprehensive evaluation value was0.676. The IR testing showed that the results were consistent with the target product.Adding sodium styrene sulfonate (SSS),2-acrylamide-2-methyl propane sulfonic acid (AMPS) or montmorillonite (MMT) as the third material on interpenetrating networks super absorbent(PAA/PVA) to change the properties, The factors that affluent the water absorbency of the resin were investigated, including the amount of SSS, AMPS and MMT. Analyzing the super absorbent resin by means of infrared spectroscopy, X-ray diffraction,thermography analysis and scanning electron mic-roscopy.The performance of four kinds of super absorbent resin were discussed and compared, including water absorption rate, gel strength, water retention capacity and multiplexing performance.Four kinds of super absorbent resin about the ability of adapting to the environment were discussed and compared. The results showed that the resin can adapt to the changes of temperature between10℃to60℃,and P(AA-SSS)/PVA super absorbent resin have the best temperature sensitivity; the water absorbent rate of resin dropped sharply under the strong acidic condition, and swelled preferably in neutral media,however, the water absorbent rate of resin declined smaller than the strong acidic condition in alkaline media,and PAA/PVA/MMT super absorbent resin have the best pH sensitivity; the tendency of absorbency for these resins in dilute solution was in the order Na+<K+<Mg2+<Ca2+; the water absorption properties of resin was slightly better in the low valence anion,and P(AA-SSS)/PVA super absor-bent resin have the best salt sensitivity.