Study On Preparation And Mechanics Of Calcined Kaolin/Sodium Polyacrylate Super Absorbent Composite

Superabsorbents can absorb a large amount of water compared with general water absorbing materials in which the absorbed water is hardly removable even under some pressure. Because of their excellent characteristics, superabsorbents are widely used in health, agriculture and horticulture applications.The study is regard to the current situation in the north of china such as little rainfall, low soil organic content, and poor water holding capacity. To reduce the production cost, simplify the production technology and improve the salt-resisting and water-holding, the research adopt the compound of calcined kaolin ultra powder in Yichang, Hubei and high polymer, and at last get calcined kaolin/sodium polyacrylate super absorbent composite. The experiment shows that it is easy to control with simple process and short cycle.The influences of acylamide content, initiator content, cross linker content and neutralization degree (all in term of the quality of acrylic acid) on the composite was studied. It shows that the optimization preparation process was determined as the content of acylamide, initiator, cross linkers and the extent of neutralization of 15%, 0.25%, 0.08%, and 80% respectively.Under the best match of previous factors, the influences of calcined kaolin addition content on water-absorbing and water-holding performance, gel intensity, repeatability and cost were studied. When the calcined kaolin addition content is 60%, the water absorption performance is the best that distilled water absorbency is 646g/g, tap water absorbency 248g/g, and physiological saline absorbency 56g/g. Compared with the composite without mineral, the retention rate is increased to 94.5% after centrifugation for 60 minutes, 61.5% after stay for 15 days in room temperature, 87.1% after stay for 6 hours in 50℃, 80.0% after stay for 6 hours in 80℃. The gel intensity is 121 g/cm~2 enhanced 43%. The water absorbency rate can reach 74% after used three times. The production cost is reduced by 5000yuan/ton.The analysis of XRD, IR and ESEM shows that the composite is composed of calcined kaolin, sodium polyacrylate, and acylamide, there is no structural change in calcined kaolin and it is dispersed homogeneously as flaky grains in polymer, and when the addition content of calcined kaolin is 60%, the compound is best.With water absorption theories of superabsorbent, water-absorbing mechanics of the composite was preliminarily researched. The result shows that calcined kaolin adheres to...