桐油包膜肥料表面及界面微观形态结构的SEM研究

Study on the surface and interface morphological microstructure of Tung oil-coated fertilizers by SEM

以桐油为主要成膜材料制备了桐油包膜尿素和桐油包膜复合肥料。用扫描电子显微镜(SEM)对包膜肥料的表面、界面及养分溶解释放后的表面进行了微观形态结构研究。结果表明:桐油能很好地分散并渗入尿素和NPK复合肥料的多孔表面形成附着良好的包膜层,在包膜率小于10%时包膜层厚度介于50～150μm之间。桐油包膜层表面具有特征的波纹状形貌,养分溶解释放后在包膜肥料的包膜层表面留下了水和养分溶液进出的凹陷通道。

A series of coated urea and coated compound fertilizer were prepared with rosin and Tung oil as film-forming materials. Morphological microstructure, such as surface, interface and surface of coated fertilizer after nutrient being released in water,was studied by scanning electron microscopy(SEM).The results shown that Tung oil could scattered and penetrate into the porous surface of the urea and compound fertilizer granule and form solid tenacious polymer film strongly bonded to the porous surface by heat curing,the thickness of coating layer was about 50～150μm as the coating rate was smaller than 10%. The coating layer of Tung-oil possessed characteristic corrugated morphology,after the nutrient being released there left the caved in passageway for water's going into and nutrient solution's going out coating layer in the surface of coated fertilizer.