Tomaszewska Maria, Jarosiewicz Anna
Institute of Chemical and Environment Engineering, Technical University of Szczecin, Pułaskiego 10, 70-322 Szczecin, Poland.
J Agric Food Chem. 2002 Jul 31;50(16):4634-9. doi: 10.1021/jf0116808.
Encapsulation of fertilizers in polymeric coatings is a method used to reduce fertilizer losses and to minimize environmental pollution. Polysulfone was used for a coating preparation for soluble NPK granular fertilizer in controlled-release fertilizer formulations. The coatings were formed by the phase inversion technique (wet method). The influence of the polymer concentration in the film-forming solution on the physical properties of the coatings was examined. The coating structure controls the diffusion of the elements from the interior of the fertilizer granule. It was experimentally confirmed that the use of polysulfone as a coating for a soluble fertilizer decreases the release rate of components. Moreover, the release rate of nutrients from coated granules decreases with the decrease of the coating porosity. In the case of coating with 38.5% porosity, prepared from 13.5% polymer solution after 5 h of test, 100% of NH(4)(+) was released, whereas only 19.0% of NH(4)(+) was released after 5 h for the coating with 11% porosity. In addition, coating of fertilizers leads to improvement of handling properties, and the crushing strength of all coated fertilizers was an average 40% higher than that for uncoated NPK fertilizer.
将肥料包裹在聚合物涂层中是一种用于减少肥料损失并将环境污染降至最低的方法。聚砜用于制备控释肥料配方中可溶性氮磷钾颗粒肥料的涂层。涂层通过相转化技术（湿法）形成。研究了成膜溶液中聚合物浓度对涂层物理性能的影响。涂层结构控制着元素从肥料颗粒内部的扩散。实验证实，使用聚砜作为可溶性肥料的涂层会降低成分的释放速率。此外，包膜颗粒中养分的释放速率随涂层孔隙率的降低而降低。对于孔隙率为38.5%的涂层，由13.5%的聚合物溶液制备，在测试5小时后，100%的NH₄⁺被释放，而对于孔隙率为11%的涂层，在5小时后只有19.0%的NH₄⁺被释放。此外，肥料包膜可改善其处理性能，所有包膜肥料的抗压强度平均比未包膜的氮磷钾肥料高40%。
