Study On The Preparation And Application Of Agricultural Super Absorbent Polymer At Sand-infertile Farmland In The Songnen Plain

Super absorbent Polymer (SAP) is a kind of new functional macromolecule polymer, which is also called water-retaining agent and the super-absorbent resin. SAP can suck up water outnumbering oneself thousands to one and has well absorbency and water retention capability. It can fully absorb irrigation water and natural rainfall, reduces water leakage and loss, and boosts utilization efficiency of water. It has a wide application prospect in agriculture. It would has particularly significance to study the application of SAP for developing agricultural drought resistance water-saving in China.In this thesis, a SAP was prepared by aqueous solution polymerization of acrylamide (AM), carboxymethyl cellulose (CMC) and humic acids (HA) using N,N-methylenebisacrylamide (MBA) as a crosslinker and potassium persulfate (KPS) as an initiator. The preparation conditions were optimized as follows:with N2 protection, reaction temperature is 60℃, m(AM)/m(CMC) is 6, m(HA)/m(CMC) is 0.2, m(MBA)/m(CMC) is 0.015, m(KPS)/m(CMC) is 0.2, the concentration of NaOH is 1.5wt%. The structure of copolymers was approved by the FT-IR analysis. The absorbability of the product reached 855.6g/g in distilled water. The results showed that the absorbability of water of the product increased along with the particles size increasing; the absorbent rate of water the product increased with the size decreasing; the capability of water conservation of the product was excellent and the time of holding water could reach over 24h under 50℃.Some indexes of the product and other four marketed SAP were measured, analyzed and evaluated, e.g., absorbability of water, absorbent rate of water, capability of water conservation, repeat time of water absorbency, water releasing property, characteristic of surface topography and the wilting point. The results showed that the absorbability and the absorbent rate of water of Dijin were excellent, but Water releasing rate is too high and Repeat time of water absorbency is lower. The absorbability and the absorbent rate of water of the prepared product were better, and the salt resistance and the repeat time of water absorbency were obvious superiority than other four SAP.In addition, some applied performances of the four marketed SAP were measured, analyzed and evaluated, such as soil moisture, emergence value of seedling, plant height, leaf area, dry weigh, the net photosynthesis rate, water use efficiency and the yield et al. According to the performances, applied technology of SAP was explored at sand-infertile farmland in the Songnen plain. Based on the results, the applied way of the medium particle size, normal amount, mixing with fertilizer or soil was suggested.