Coated granular fertilizers, methods of manufacture thereof, and uses thereof
A coated fertilizer comprising a fertilizer granule and a coating disposed on a surface of the fertilizer granule, wherein the coating comprises interpenetrating domains comprising polymer domains and wax domains. A method of making the coated fertilizer is also disclosed.
1. A process of manufacturing a coated fertilizer comprising a fertilizer granule and a coating disposed on a surface of the fertilizer granule, wherein the coating comprises a biodegradable polymer and a wax, wherein the polymer forms a coating comprising cracks and/or pinholes on the surface of the fertilizer granule, and wherein the wax seals at least a majority of the cracks and/or pinholes, the process comprising:
contacting the fertilizer granule and/or a wax coating with the polymer to form a polymer coating comprising cracks and/or pinholes on the surface of the fertilizer granule; and
contacting the polymer coating and/or fertilizer granule with the wax to form a wax and polymer coated fertilizer granule wherein the wax seals at least a majority of the cracks and/or pinholes,
wherein the polymer comprises poly(butylene succinate), wherein the coating comprises at least a portion of the wax within the coating, and wherein at least a portion of the wax is located between the fertilizer granule and at least a portion of the polymer.
2. The process of claim 1 , wherein contacting the fertilizer granule with the polymer comprises contacting the fertilizer granule with a first solution comprising the polymer at least partially dissolved in a first organic solvent.
3. The process of claim 2 , wherein the polymer coating further comprises an additional polymer, the polymer and additional polymer each having a different rate of biodegradation under the same conditions, wherein the fertilizer granule is contacted with a second solution comprising the additional polymer at least partially dissolved in a second organic solvent.
4. The process of claim 3 , wherein the first and second organic solvents are evaporated from the respective first solution and second solution.
5. The process of claim 2 , wherein contacting the fertilizer granule with the polymer further comprises evaporating the first organic solvent from the first solution.
6. The process of claim 1 , wherein the process further comprises heating the wax and polymer coated fertilizer granule at a temperature effective to at least partially melt the wax.
7. The process of claim 6 , wherein the temperature effective to at least partially melt the wax is 30° C. to 130° C.
8. The process of claim 1 , wherein the polymer coating further comprises an additional polymer, the polymer and additional polymer each having a different rate of biodegradation under the same conditions.
9. The process of claim 1 , further comprising applying additional wax to the wax and polymer coated fertilizer granule while heating the wax and polymer coated fertilizer granule at a temperature effective to at least partially melt the wax and the additional wax.
10. A coated fertilizer, comprising:
a fertilizer granule; and
a coating disposed on a surface of the fertilizer granule, wherein the coating comprises a biodegradable polymer and a wax, wherein the polymer comprises poly(butylene succinate), wherein the polymer forms a coating comprising cracks and/or pinholes on the surface of the fertilizer granule, wherein the wax seals at least a majority of the cracks and/or pinholes, wherein the coating comprises at least a portion of the wax within the coating, and wherein at least a portion of the wax is located between the fertilizer granule and at least a portion of the polymer.
11. The coated fertilizer of claim 10 , wherein the wax forms a non-continuous coating on the surface of the fertilizer granule.
12. The coated fertilizer of claim 10 , wherein the fertilizer granule comprises urea.
13. The coated fertilizer of claim 10 , wherein the wax does not form an overcoat that covers the entire surface of the coated fertilizer.
14. The coated fertilizer of claim 10 , wherein the polymer comprises at least two polymers.
15. The coated fertilizer of claim 10 , wherein the polymer further comprises poly(lactic acid).
16. The coated fertilizer of claim 10 , wherein the wax comprises a C 5 -C 35 wax.
17. The coated fertilizer of claim 10 , wherein the polymer has a first rate of biodegradation and the wax has a second rate of biodegradation that differs from the first rate under the same conditions.
18. The coated fertilizer of claim 10 , wherein the polymer comprises at least two polymers, each having a different rate of biodegradation under the same conditions.