【摘要】 将木质素这一廉价且环保的原料作为包膜尿素的包膜材料并完善包膜尿素的制备工艺具有重要意义。本试验以木质素、辛酸亚锡、六亚甲基异氰酸酯和聚乙二醇为原料制备木质素基膜材，以此作为包膜尿素的内层，将环氧树脂基包膜液喷涂在木质素基包膜尿素颗粒表面作为外层，得到木质素/环氧树脂基复合包膜尿素。通过调控-NCO/-OH的摩尔比和包膜率来探究包膜尿素的最佳制备条件，并通过静水培养试验测试其累积养分释放率。在此基础上，选择最优养分释放性能的包膜尿素，评估其表面形貌和抗压性能之间的差异。结果表明，-NCO/-OH的摩尔比为1.50时，木质素基膜材的最大热解温度和水接触角分别为404.31℃和82.36°。-NCO/-OH的摩尔比和包膜率均与包膜尿素的养分释放期呈正相关。在-NCO/-OH摩尔比为1.50、树脂含量为40%、包膜率为7%的条件下，包膜尿素的养分释放性能最佳，其释放80%养分所需时间大于30 d。这种采用木质素为原料制备的包膜尿素符合国家控释肥料标准。本研究结果为绿色、经济包膜尿素的发展提供了理论依据和技术支撑。更多还原

【Abstract】 It is very important to use lignin, a cheap and environmentally friendly raw material, as the coating material of coated urea and to improve the preparation process of coated urea. In this experiment, lignin, stannous octoate, hexamethylene isocyanate and polyethylene glycol are used as raw materials to obtain lignin-based membrane, which was used as the inner layer of coated urea. Subsequently, the epoxy resin-based coating liquid was sprayed on the surface of the lignin-based coated urea particles as an outer layer to obtain a lignin/epoxy resin-based composite coated urea. The optimal preparation conditions of the coated urea were explored by adjusting the molar ratio of-NCO/-OH and the coating rate, and the cumulative nutrient release rate was tested by static water culture test. On this basis, the coated urea with optimal nutrient release performance was selected to evaluate the difference between its surface morphology and compressive properties. When the molar ratio of-NCO/-OH was 1. 50, the maximum pyrolysis temperature and water contact angle of the ligninbased membrane were 404. 31 ℃ and 82. 36°, respectively. The results of hydrostatic test showed that the molar ratio of-NCO/-OH and the coating rate were positively correlated with the nutrient release period of the coated urea. Under the conditions of-NCO/-OH molar ratio of 1. 50, resin content of 50%, and coating rate of 7%, the nutrient release performance of the coated urea was the optimal, and the time required to release 80%of the nutrients was more than 30 days. Coated urea prepared in this study meets the national standard of controlled release fertilizer. This study will provide theoretical basis and technical support for development of green and economical coated urea.更多还原