Shen Yazhen, Du Changwen, Zhou Jianmin, Ma Fei
State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences , 71 East Beijing Road, Nanjing 210008, China.
J Agric Food Chem. 2017 Feb 8;65(5):1030-1036. doi: 10.1021/acs.jafc.6b05274. Epub 2017 Jan 30.
Acrylic latexes are valuable waterborne materials used in controlled-release fertilizers. Controlled-release urea coated with these latexes releases a large amount of nutrients, making it difficult to meet the requirement of plants. Herein, Fe-tannic acid (TA) complexes were blended with acrylic latex and subsequently reassembled on a surface of polyacrylate particles. These complexes remarkably retarded the release of urea (the preliminary solubility was decreased from 22.3 to 0.8%) via decreasing the coating tackiness (T was increased from 4.17 to 6.42 °C), increasing the coating strength (tensile stress was improved from 3.88 to 4.45 MPa), and promoting the formation of denser structures (surface tension was decreased from 37.37 to 35.94 mN/m). Overall, our findings showed that a simple blending of Fe-TA complexes with acrylic latex produces excellent coatings that delay the release of urea, which demonstrates great potential for use in controlled-release fertilizers coated with waterborne polymers.
丙烯酸乳胶是用于控释肥料的重要水性材料。用这些乳胶包覆的控释尿素会释放大量养分，难以满足植物的需求。在此，将铁-单宁酸（TA）络合物与丙烯酸乳胶混合，随后在聚丙烯酸酯颗粒表面重新组装。这些络合物通过降低涂层粘性（T从4.17℃提高到6.42℃）、提高涂层强度（拉伸应力从3.88MPa提高到4.45MPa）以及促进形成更致密的结构（表面张力从37.37mN/m降低到35.94mN/m），显著延缓了尿素的释放（初始溶解度从22.3%降至0.8%）。总体而言，我们的研究结果表明，将铁-单宁酸络合物与丙烯酸乳胶简单混合可制备出优异的涂层，从而延缓尿素的释放，这表明其在水性聚合物包覆的控释肥料中具有巨大的应用潜力。
