丙烯酸树脂包膜尿素肥料研制及其控释效果

采用丙烯酸树脂为包膜材料,以NBPT（N-丁基硫代磷酰三胺）和DCD（双氰胺）为生化抑制剂,利用流化床对尿素进行涂层生化抑制剂及包膜,制备4种包膜肥料,对这些包膜肥料在水中的控释效果进行了研究。结果表明,采用此技术制备的包膜肥料,表面成膜完整,包膜物质在成膜时分布均匀、与尿素肥心接合紧密,表面光滑。NBPT和DCD与肥心结合严密,包膜层紧覆于抑制剂的外表。包膜可有效控制尿素的溶出,在水中的控释时间为19～30d。初期溶出率远远小于15％,微分溶出率基本上在0．25％～2．5％之间;在水中尿素累积溶出特征符合一元二次方程模型,尿素释放曲线呈“S”形。

Preparation of acrylic resin coated urea fertilizers and their controlled effects

Acrylic resin as coated material, N-(n-butyl) thiophosphric triamide(NBPT) and dicyandiamde(DCD) as biological inhibitors, with Fluid Bed spraying biological inhibitors on urea granular surface and coated it with acrylic resin afterward, four coated urea fertilizers were made for monitoring slow/controlled effects of coated fertilizers in distilled water. The results show that the film is integrated on urea core surface, coated material is uniformity distributing with coating and combining with urea core close, and the surface is smooth. NBPT and DCD combined with urea core closely, coating layer covered closely the inhibitors surface in the coated fertilizers made by such a technology. The film was able to control urea release availably. The release date was between 19 d and 30 d in distilled water. The preliminary solubility was lower than 15%, and differential solubility was between 0.25% and 2.5% approximately. The correlation of accumulative urea nitrogen released from coated fertilizers in distilled water with time was found to conform to a quadric equation in one variable, with "S" pattern curve for the urea nitrogen accumulative release rate of the coated urea.