Liang Rui, Liu Mingzhu
Department of Chemistry, Lanzhou University, Lanzhou 730000, People's Republic of China.
J Agric Food Chem. 2006 Feb 22;54(4):1392-8. doi: 10.1021/jf052582f.
A double-coated, slow-release, and water-retention urea fertilizer (DSWU) was prepared by cross-linked poly(acrylic acid)-containing urea (PAAU) (the outer coating), polystyrene (PS) (the inner coating), and urea granule (the core). Elemental analysis results showed that the nitrogen content of the product was 33.6 wt %. The outer coating (PAAU) regulated the nitrogen release rate and protected the inner coating from damage. The slow-release property of the product was investigated in water and in soil. The possible mechanism of nitrogen release was proposed. The influences of PS coating percentage, temperature, water absorbency, and pH on the release of nitrogen were also investigated. It was found that PS coating percentage, temperature, and water absorbency had a significant influence on the release of nitrogen. However, the pH had no effect. The water-retention property of the product was also investigated. The results showed that the product not only had a good slow-release property but also excellent water-retention capacity, which could effectively improve the utilization of fertilizer and water resources. The results of the present work indicated that the DSWU would find good application in agriculture and horticulture, especially in drought-prone areas where the availability of water is insufficient.
一种双层包膜、缓释且保水的尿素肥料（DSWU）由含交联聚丙烯酸的尿素（PAAU）（外层包膜）、聚苯乙烯（PS）（内层包膜）和尿素颗粒（核心）制备而成。元素分析结果表明，该产品的氮含量为33.6 wt%。外层包膜（PAAU）调节氮释放速率并保护内层包膜免受损害。在水和土壤中研究了该产品的缓释性能。提出了氮释放的可能机制。还研究了PS包膜百分比、温度、吸水性和pH对氮释放的影响。发现PS包膜百分比、温度和吸水性对氮释放有显著影响。然而，pH没有影响。还研究了该产品的保水性能。结果表明，该产品不仅具有良好的缓释性能，而且具有优异的保水能力，可有效提高肥料和水资源的利用率。目前的工作结果表明，DSWU将在农业和园艺中得到良好应用，特别是在水资源匮乏的干旱地区。
