Preparation And Properties Of Mineral-based Superabsorbent Composite

At present in view of the cost of superabsorbent composite is too high, the researchs on composite mechanism are too few and the technology is out of joint with production, preparation and property of mineral-based superabsorbent composite with high mineral content and low cost are researched. The Ca-bentonite from huludao, Liaoning is chosen from different types, areas clay as the raw material. The composite prepared by polymer and bentonite is analyzed by IR, XRD and SEM. The composite mechanism of bentonite/polymer is discussed.30%bentonite is considered to be uniformly dispersed in polymer by grafted on the molecular chain. It has the function of cross link.The compositions and processes factors determined the water absorbency of product are discussed on the theory of one factor optimization. The optimum formula is as follow: mass fraction of bentonite is30%, n(acrylic acid)/n(acrylamide)=0.8, using potassium hydrate as neutralizing agent, neutralization ratio of acrylic acid is80%, m(MBA)/m(total monomers) is6.15×10-3%, n(total initiators)/n(total monomers) is5.73×10-2%, n[(NH4)2S2O8]/n(V50)=3.12, n[(NH4)2S2O8]/n(NaHSO3)=1.1, the temperature of adding sodium bisulfate is30℃. Under these conditions, the water absorbency is765g/g, the saline absorbency (0.9%NaCl) is56g/g.A series of technical methods are used for improving salt resistance and water retention. The saline absorbency (0.9%NaCl) is raised from56g/g to68g/g by adding10%AMPS of the total monomers. The water retention is improved by spraying surface cross-link treatment solution(5%).Bench-scale research is performed in tank reactor.800kg product is produced. The water absorbency of the sample is690g/g, and saline absorbency (0.9%NaCl) is53g/g.