| 摘要 |
A method of forming an encapsulated fertilizer comprises the step of providing a core particle. The core particle comprises a fertilizer and has an outer surface. An example of the fertilizer is urea. The method further comprises the step of applying an isocyanate component directly to the outer surface of the core particle. The isocyanate component has isocyanate functional groups. An example of the isocyanate component is an isocyanate-terminated prepolymer. A specific example of the isocyanate-terminated prepolymer is one comprising the reaction product of a diphenylmethane diisocyanate (MDI) and a polyol. The method further comprises the step of reacting the isocyanate component with ambient moisture to form a layer disposed about the core particle to form the encapsulated fertilizer. The layer comprises polyurea linkages. The layer may further comprise polyurethane linkages. For example, the layer may be in the form of a polyurea/polyurethane layer when the isocyanate-terminated prepolymer is utilized. |
