Research On The Graft Copolymer Aquasorb Synthesis Process And Application

The super absorbent polymer is a synthetic polymer, which is called insuranceagent in the agriculture. It has good water absorption, which can absorb and retainseveral times to a thousand times of its own weight of distilled water, as well as0.9%saline. Retaining agent also has excellent water retention and repeat suction capacity.In recent years, researchers are caring out some exploration about combining aspectsof superabsorbent and fertilizers. If water, fertilizer and insurance agent can achieve abetter coupling effect, increasing the efficiency of fertilizer will have a significantimpact on China’s agriculture.Solution polymerization method is used in this study with corn starch andindustrial grade attapulgite as graft material, acrylic acid and acrylamide as monomer.According to design orthogonal experiment and single factor experiment, we canknow the impact of the monomer ratio, attapulgite content and initiator content onretaining agent absorbency. By analyzing orthogonal experiments, Shippingexperimental conditions can be found. The performance of super absorbent polymerwas characterized by FTIR,SEM and DSC. The performances of instant suction rate,water capacity and repeat suction capacity were tested; On the basis of the optimumexperimental conditions, insurance agent which contain N, P, K were obtained byadding different amounts of urea, phosphate, potash. The absorbency,24h sustainedrelease and sustained-release of seven days were determined. The results andconclusions are as follows:1. Shipping experimental conditions: the polymerization temperature is70, theratio of starch to AA to AM is1:5:1and the content of attapulgite soil is8%. Whenthe temperature reached to the polymerization temperature, corn starch, attapulgiteand monomer were added to the polymerization. The content of cross-linking agent is0.06%and initiator content is0.5%. Water absorbency rate and salt absorbency rateof the polymer are389.6g/g and58.9g/g, respectively. The result of differentialscanning calorimetry show that it has very good thermal stability. The results of infrared indicate that the starting materials are involved in the polymerization reactionfrom the aspect of chemical structure. The physical structure electron microscopyproves its good water absorption.2. When the contents of anions are the same amount, the influence of cations onthe suction rate is: Al3+> Ca2+> Mg2+> K+> NH4+> Na+. When the contents of cationsare same, the influence of anions on the suction rate is: SO32->CO32->SO42->HCO3->HPO42->SiO32-. After11days the water absorbing resin lose all the water, whichproves that ionic-non-ionic type composite resin has good water retention capacityunder natural conditions. The absorbency of retaining agent is still111.9g/g afterbeing heated at220℃; under normal circumstances, the super absorbent resin hasgood thermal stability.3. The average absorbencies of N, P and K for insurance agent are about100g/g.The salt absorption rate is generally30-50g/g. For potassium insurance agent,7dnutrient release rate is75.8%,which is in line with slow/controlled release fertilizerstandards.