Coated Slow-release Urea Preparation Of Membranes And Through Fertilizer

The paper explored the process of preparing UF resin. The ways to enhance the toughness and water resistance properties of UF resin were discussed. UF resin membranes as well as the UF-ZB composite membranes and UF-ZA composite membranes with different thickness were prepared. A research was made on the urea permeation performance of the membranes mentioned.UF resin, as a kind of nitrogenous fertilizer, is an envelope material with the advantages of low cost and high nitrogen contents. However, UF resin has high brittleness and is easy to be fractured. PVA, para toluene sulfonamide and malamine were added to the UF preformed polymer so as to improve the chemical properties of UF resin. The effect of modifiers on shear strength and water resistant performance of UF resin was studied and compared. The results show that the brittleness performance of UF resin is improved obviously by PVA modifier, and the water resistance performance is better due to the malamine modifier.The urea permeation performance of the membranes suggests that the cumulate permeation value is increased with the increasing of membrane thickness. Among the UF resin membranes, the cumulate urea permeation in seven days of the PVA modified UF resin membrane, which is prepared with 3wt% PVA account in overall raw material, is the largest. The cumulate urea permeation of the malamine modified UF resin membrane, which is prepared with the account of malamine being 5 wt% of urea account, is the least. The cumulate urea permeations of the UF-ZB and UF-ZA composite membranes are much smaller than that of the UF resin membranes. The cumulate urea permeation of the UF-ZB composite membrane is larger than that of the UF-ZA composite membrane.