Preparation And Properties Of Membranes Of. Sustained And Controlled Release Fertilizers

The modified synthetic of the urea-formaldehyde (UF) resin prepolymer was explored. For the purpose of modification, we added the auxiliary of P and filler of M to the system when the UF prepolymer was synthesized. In order to give research on their participation in the case of reaction, the treated and untreated filler of M were characterized, respectively, such as Sedimentation test, FTIR, TGA, DTA and XRD. At the same time, we studied the influence of the amount of filler M added on the UF prepolymers viscosity, shear strength and thermal properties. Beside these, we also use SEM to study the cross-section of UF resin. In addition, the different components and different thickness of the various modified UF resin membrane were prepared to study its ability in hamper of urea.As the coating materials, UF resin has many advantages, such as low-cost and high nitrogen contents, and it's slow-release nitrogen fertilizer in itself. In the paper, we added the auxiliary of P and filler of M to the system, and studied the results of the modification. The results show that the viscosity and shear strength of the modified UF prepolymer have been significantly enhanced, and with the increasing amount of M, the thermal decomposition of UF resin moved to a higher temperature. At the same time, the SEM observation shows that with the volume of filler increasing, filler distributed more even in the resin and had no reunion.These show that the dispersion of filler is better.In the paper, our study shows that the amount of urea through the membrane was reduced with the increase of the membrane's thickness.With the same thickness, the UF membrane which contained both P and M has a greater through volume than the UF membrane which only contain P. With the same thickness and content of P, the number of urea through the UF membrane increases with the increase of the content of M.